Trump's paternal grandfather, Friedrich Trump, first emigrated to the United States in 1885 at the age of 16 and became a citizen in 1892. He amassed a fortune operating boom-town restaurants and boarding houses in the Seattle area and the Klondike region of Canada during its gold rush. On a visit to Kallstadt, he met Elisabeth Christ and married her in 1902. The couple permanently settled in New York in 1905. Frederick died from influenza during the 1918 pandemic.

Trump's father Fred was born in 1905 in The Bronx. Fred started working with his mother in real estate when he was 15, shortly after his father's death. Their company, Elizabeth Trump & Son, was primarily active in the New York boroughs of Queens and Brooklyn. Fred eventually built and sold thousands of houses, barracks, and apartments. The company was later renamed The Trump Organization, after Donald Trump took charge in 1971.

Trump's mother Mary Anne was born in Tong, Lewis, Scotland. At age 18 in 1930, she emigrated to New York, where she worked as a maid. Fred and Mary were married in 1936 and raised their family in Queens.

Trump's ancestors were Lutheran on his father's side in Germany and Presbyterian on his mother's side in Scotland. His parents married in a Manhattan Presbyterian church in 1936. As a child, he attended the First Presbyterian Church in Jamaica, Queens, and had his Confirmation there. In the 1970s, his family joined the Marble Collegiate Church (an affiliate of the Reformed Church in America) in Manhattan. The pastor at that church, Norman Vincent Peale, author of The Power of Positive Thinking and The Art of Living, ministered to Trump's family and mentored him until Peale's death in 1993. Trump, who is Presbyterian, has cited Peale and his works during interviews when asked about the role of religion in his personal life.

Donald John Trump was born on June 14, 1946, at the Jamaica Hospital Medical Center, Queens, New York City, the fourth of five children. Trump grew up in Jamaica, Queens, and attended the Kew-Forest School from kindergarten through seventh grade. At age 13, he enrolled in the New York Military Academy, a private boarding school, after his parents discovered that he had made frequent trips into Manhattan without their permission.

Trump did not serve in the military during the Vietnam War. While in college from 1964 to 1968, he obtained four student deferments. In 1966, he was deemed fit for Service based upon a military medical examination, and in 1968 was briefly Classified as eligible to serve by a local draft board. In September of that year, he was given a medical deferment, which he later attributed to heel spurs. In 1969, he received a high number in the draft lottery, which gave him a low probability to be called to military Service.

Two days later, Trump officially accepted the nomination in a 76-minute speech that was inspired by Richard Nixon's 1968 acceptance speech. The historically long speech was watched by nearly 35 million people and received mixed reviews, with net negative viewer reactions according to CNN and Gallup polls.

After Trump took over the family real estate firm in 1971 and renamed it The Trump Organization, he greatly expanded its real estate operations and ventured into numerous other Business activities. The company eventually became the umbrella organization for several hundred individual Business ventures and partnerships.

Trump has a history of making racially-charged statements and taking actions that are perceived as racially motivated. In 1975, he settled a 1973 lawsuit brought by the United States Department of Justice that alleged housing discrimination against black renters. He was accused of racism for insisting that a group of black and Latino teenagers were guilty of raping a white woman in the 1989 Central Park jogger attack even after they were exonerated by DNA evidence in 2002. He continued to maintain this position as late as 2016.

New Jersey legalized casino gambling in 1977, and Trump went to Atlantic City, New Jersey the following year in order to explore how he might get involved in a new Business venture. Seven years later, Harrah's at Trump Plaza hotel and casino opened there; the project was built by Trump with financing from the Holiday Corporation, which also managed the operation. Renamed "Trump Plaza" soon after it opened, it was at the time the tallest building in Atlantic City. The casino's poor financial results exacerbated disagreements between Trump and Holiday Corp., which led to Trump's paying $70 million in May 1986 to buy out their interest in the property. Trump also acquired a partially completed building in Atlantic City from the Hilton Corporation for $320 million; when completed in 1985, that hotel and casino became Trump Castle, and Trump's wife Ivana managed that property until 1988.

Also in 1978, Trump finished negotiations to develop Trump Tower, a 58-story, 202-meter (663-foot) skyscraper in Midtown Manhattan, which The New York Times attributed to his "persistence" and "skills as a negotiator". To make way for the new building, a crew of undocumented Polish workers demolished an old Bonwit Teller store, including art deco features that had initially been marked for preservation. The building was completed in 1983 and houses both the primary penthouse condominium residence of Trump and the headquarters of The Trump Organization. Architectural critic Paul Goldberger said in 1983 that he was surprised to find the tower's atrium was "the most pleasant interior public space to be completed in New York in some years". Trump Tower was the setting of the NBC television show The Apprentice and includes a fully functional television studio set.

According to a New York state report, Trump circumvented corporate and personal campaign donation limits in the 1980s—although no laws were broken—by donating money to candidates from 18 different Business subsidiaries, rather than donating primarily in his own name. Trump told investigators he did so on the advice of his lawyers. He also said the contributions were not to gain favor with business-friendly candidates, but simply to satisfy requests from friends.

Trump does not drink alcohol; this decision arose in part from watching his older brother Fred Jr. suffer from alcoholism that contributed to his early death in 1981. He also said that he has never smoked cigarettes or consumed drugs, including marijuana.

Trump said that he began his career with "a small loan of one million dollars" from his father. He appeared on the initial Forbes 400 list of wealthy individuals in 1982 with an estimated $200 million fortune, including an "undefined" share of his parents' estate. During the late 1980s he became a Billionaire, and he made the Forbes World's Billionaires list for the first time in 1989, but he was absent from the Forbes 400 list following Business losses from 1990 to 1995; he reportedly borrowed from his siblings' trusts in 1993. His father's estate, valued at more than $20 million, was divided in 1999 among Trump, his three surviving siblings, and their children.

In September 1983, Trump purchased the New Jersey Generals—an American football team that played in the United States Football League (USFL)—from oil magnate J. Walter Duncan. The USFL played three seasons during the spring and summer. After the 1985 season, the organization folded due to continuous financial difficulties, despite winning an antitrust lawsuit against the NFL.

In 1985, Trump acquired the Mar-a-Lago estate in Palm Beach, Florida for under $8 million. The home was built in the 1920s by heiress and socialite Marjorie Merriweather Post, who envisioned the house as a Future winter retreat for American Presidents.

In 1986, Trump acquired a foreclosed 33-story, twin-tower condominium complex in nearby West Palm Beach for $40 million. Auto CEO Lee Iacocca invested in three of the condos. Trump spruced up the complex's public areas and heavily promoted the property for years, but selling the units proved difficult, and the deal turned out to be unprofitable.

Trump's political party affiliation has changed numerous times over the years. Trump was a Democrat prior to 1987; Trump registered as a Republican in Manhattan. In 1987 Trump vaguely expressed interest in running for the presidency when he spent almost $100,000 to place full-page advertisements in three major newspapers. In his view at that time, "America should stop paying to defend countries that can afford to defend themselves". The advertisements had also advocated for "reducing the budget deficit, working for peace in Central America, and speeding up nuclear disarmament negotiations with the Soviet Union." After rumors of a presidential run, he was then invited by Democratic senators Jim Wright and John Kerry, and Arkansas congressman Beryl Anthony Jr., to host a fundraising dinner for Democratic Congressional candidates and to switch parties. Anthony told The New York Times that "the message Trump has been preaching is a Democratic message". Asked whether the rumors were true, Trump denied he was a candidate and said, "I believe that if I did run for President, I'd win." According to a Gallup poll in December 1988, Trump was the tenth most admired person in America.

Trump is a World Wrestling Entertainment fan and a friend of WWE chairman Vince McMahon. In 1988 and 1989, he hosted WrestleMania IV and V at Boardwalk Hall and has been an active participant in several of the shows. He appeared at WrestleMania VII in 1991 and WrestleMania XX in 2004. He cornered Bobby Lashley at 2007's WrestleMania 23, who pinned McMahon's Umaga in a match called "The Battle of the Billionaires", with each mogul's hair on the line. In 2013, he was inducted into the Celebrity wing of the WWE Hall of Fame at Madison Square Garden for his contributions to the promotion. He made his sixth WrestleMania appearance the following night at WrestleMania 29. As President, Trump appointed WWE CEO Linda McMahon to his Cabinet as Administrator of the Small Business Administration.

Trump won 30 states including the perennial swing states of Florida and Iowa. He also won Ohio and Clinton's "blue wall" states of Michigan, Pennsylvania, and Wisconsin, which had been Democratic strongholds since the 1990s. Clinton won 20 states and the District of Columbia. Trump's victory marked the return of a Republican White House combined with control of both chambers of Congress.

The six bankruptcies were the result of over-leveraged hotel and casino businesses in Atlantic City and New York: Trump Taj Mahal (1991), Trump Plaza Hotel and Casino (1992), Plaza Hotel (1992), Trump Castle Hotel and Casino (1992), Trump Hotels and Casino Resorts (2004), and Trump Entertainment Resorts (2009). Trump said, "I've used the laws of this country to pare debt ... We'll have the company. We'll throw it into a chapter. We'll negotiate with the banks. We'll make a fantastic deal. You know, it's like on The Apprentice. It's not personal. It's just Business."

In October 1993, Maples gave birth to Trump's daughter, who was named Tiffany after high-end retailer Tiffany & Company. Maples and Trump were married two months later in December 1993. They divorced in 1999, and Tiffany was raised by Marla in California.

From 1994 to 2002, Trump owned a 50% share of the Empire State Building. He would have renamed it "Trump Empire State Building Tower Apartments" if he had been able to boost his share.

In 1995, Trump founded Trump Hotels & Casino Resorts (THCR), which assumed ownership of Trump Plaza, Trump Castle, and the Trump Casino in Gary, Indiana. THCR purchased Taj Mahal in 1996 and underwent bankruptcy restructuring in 2004 and 2009, leaving Trump with 10% ownership in the Trump Taj Mahal and other Trump casino properties. From mid 1995 until early 2009, he served as chairman of the publicly-traded THCR organization—which was renamed Trump Entertainment Resorts—and served as CEO from mid 2000 to mid 2005.

From 1996 to 2015, Trump owned part or all of the Miss Universe pageants. The pageants include Miss USA and Miss Teen USA. His management of this Business involved his family members—daughter Ivanka once hosted Miss Teen USA. Trump hired the first female President of the Miss Universe Business in 1997. He became dissatisfied with how CBS scheduled the pageants, and took both Miss Universe and Miss USA to NBC in 2002.

In 1997, he began construction on Riverside South, which he dubbed Trump Place, a multi-building development along the Hudson River. The project encountered delays the following year because a subcontractor had to replace defective concrete. He and the other Investors in the project ultimately sold their interest for $1.8 billion in 2005 in what was then the biggest residential sale in the history of New York City.

In 1999, Trump told Larry King Live that "I believe in universal Health care." Trump's 2000 book, The America We Deserve, argued strongly for a single-payer Health care system based on the Canadian model, and has voiced admiration for the Scottish National Health Service. Trump says he aims to streamline the Department of Veterans Affairs, get rid of backlogs and waitlists, and upgrade relevant facilities. On his first Monday in office, Trump issued a federal hiring freeze on the VA.

Trump has been the subject of comedians, flash cartoon artists, and online caricature artists. He has been parodied regularly on Saturday Night Live by Phil Hartman, Darrell Hammond, and Alec Baldwin, and in South Park as Mr. Garrison. The Simpsons episode "Bart to the Future", written during his 2000 campaign for the Reform party, anticipated a Future Trump presidency. A dedicated parody series called The President Show debuted in April 2017.

In 2001, Trump completed Trump World Tower, which was across from the headquarters of the United Nations. For a while, the structure was the tallest all-residential tower in the world. In 2002, Trump acquired the former Hotel Delmonico, which was renovated and reopened in 2004 as the Trump Park Avenue; the building consisted of 35 stories of luxury condominiums.

In 2003, Trump became the executive Producer and host of the NBC reality show The Apprentice, in which contestants competed for a high-level management job in one of Trump's businesses, and were successively "fired" and eliminated from the game. During the first year of the show, Trump earned $50,000 per episode (roughly $700,000 for the first season), but following the show's initial success, he was paid $1 million per episode. The Apprentice was nominated for an Emmy Award in 2004 and 2005. In 2007, Trump received a star on the Hollywood Walk of Fame for his contribution to television on The Apprentice.

Trump also considered running for President in 2004. From 2001 to 2008, Trump identified himself as a Democrat, but, in 2008, he endorsed Republican John McCain for President. In 2009, he officially changed his party registration to Republican.

Two days before the second presidential debate, a 2005 recording surfaced in which Trump was heard bragging about forcibly kissing and groping women. The hot mic recording was captured on a studio bus in which Trump and Billy Bush were preparing to film an episode of Access Hollywood. "I just start kissing them," Trump said, "I don't even wait. And when you're a star, they let you do it, you can do anything ... grab them by the pussy." During the recording, Trump also spoke of his efforts to seduce a married woman, saying he "moved on her very heavily." These statements were recorded several months after Trump married his third and current wife, Melania, who was pregnant at the time.

Trump has made cameo appearances in 12 films and 14 television series. He played an oil tycoon in The Little Rascals, and had a singing role at the 58th Primetime Emmy Awards in 2006. Trump is a member of the Screen Actors Guild and receives an annual pension of more than $110,000.

Trump played a leading role in "birther" conspiracy theories that had been circulating since President Obama's 2008 presidential campaign. Beginning in March 2011, he publicly questioned Obama's citizenship and eligibility to serve as President. Although the Obama campaign had released a copy of the short-form birth certificate in 2008, Trump demanded to see the original "long-form" certificate. He mentioned having sent investigators to Hawaii to research the question, but he did not follow up with any findings. He also repeated a debunked allegation that Obama's grandmother said she had witnessed his birth in Kenya. When the White House later released Obama's long-form birth certificate, Trump took credit for obtaining the document, saying "I hope it checks out." His official biography mentions his purported role in forcing Obama's hand, and he has defended his pursuit of the issue when prompted, later saying that his promotion of the conspiracy made him "very popular". In 2011, he had called for Obama to release his student records, questioning whether his grades warranted entry into an Ivy League school. He also claimed in his 2011 CPAC speech that Obama's classmates "don't know who he is". When asked in 2015 whether he believed Obama was born in the United States, he said he did not want to discuss the matter further. In September 2016, he publicly acknowledged Obama's birthplace, and claimed, falsely, that the rumors had been started by Hillary Clinton during her 2008 presidential campaign.

Trump's presence on social media has attracted attention worldwide since he joined Twitter in March 2009. He communicated heavily on Twitter during the 2016 election campaign, and has continued to use this channel during his presidency. The attention on Trump's Twitter activity has significantly increased since he was sworn in as President. Many of the assertions tweeted by Trump have been proven to be false. Two-thirds of Americans dislike his "use of Twitter", according to a July 2017 ABC News/Washington Post poll.

Trump has made contributions to campaigns of both Republican Party and Democratic Party candidates, with the top ten recipients of his political contributions being six Democrats and four Republicans. After 2011, his campaign contributions were more favorable to Republicans than to Democrats.

The Deferred Action for Childhood Arrivals program (DACA) had been introduced in 2012 by President Obama to handle the cases of people who had either entered or remained in the United States illegally as minors. Those individuals, nicknamed "Dreamers", could receive a renewable two-year period of deferred action from deportation and were eligible for a work permit. While running for President, Trump said that he intended to repeal DACA on "day one" of his presidency.

Trump's immigration policies were a topic of intense discussion during the campaign. He promised to build a more substantial wall on the Mexico–United States border to keep out illegal immigrants and vowed that Mexico would pay for it. He pledged to massively deport illegal immigrants residing in the United States, and criticized birthright citizenship for creating "anchor babies". He said that deportation would focus on Criminals, visa overstays, and security threats.

Fact-checking organizations have denounced Trump for making a record number of false statements compared to other candidates. At least four major publications—Politico, The Washington Post, The New York Times, and the Los Angeles Times—have pointed out lies or falsehoods in his campaign statements. NPR said that Trump's campaign statements were often opaque or suggestive. Lucas Graves, an assistant professor of journalism and mass communication at the University of Wisconsin–Madison, opined that Trump "often speaks in a suggestive way that makes it unclear what exactly he meant, so that fact-checkers have to be really careful to pick things that reflect what the speaker was clearly trying to communicate."

In order to confront the Islamic State of Iraq and Syria (ISIS), Trump in 2015 called for seizing the oil in ISIS-occupied areas, using U.S. air power and ground troops. In 2016, Trump advocated sending 20,000 to 30,000 U.S. troops to the region, a position he later retracted.

One of Trump's campaign managers, Paul Manafort, had worked for several years to help pro-Russian Politician Viktor Yanukovich win the Ukrainian presidency. Other Trump associates, including former National Security Advisor Michael T. Flynn and political consultant Roger Stone, have been connected to Russian officials. Russian agents were overheard during the campaign saying they could use Manafort and Flynn to influence Trump. Members of Trump's campaign and later his White House staff, particularly Flynn, were in contact with Russian officials both before and after the November election. In a December 29, 2016, conversation, Flynn and Kislyak discussed the recently imposed sanctions against Russia; Trump later fired Flynn for falsely claiming he had not discussed the sanctions.

Trump signaled his intention to run for a second term by filing with the FEC within hours of assuming the presidency. This transformed his 2016 election committee into a 2020 reelection one. Trump marked the official start of the campaign with a campaign rally in Melbourne, Florida, on February 18, 2017, less than a month after taking office. By January 2018, Trump's reelection committee had raised $22.1 million.

In January 2018, The Washington Post reported that Mueller wants to interview Trump about the removal of Michael Flynn and James Comey. Trump has expressed a willingness to do the interview; according to The New York Times, some of his lawyers have warned against doing so. Mueller can subpoena Trump to testify if Trump refuses.

During his campaign, Trump repeatedly vowed to repeal and replace Obamacare. Shortly after taking office, he urged Congress to repeal and replace it. In May of that year, the United States House of Representatives voted to repeal the ACA. Over the course of several months' effort, however, the Senate was unable to pass any version of a repeal bill. Trump has expressed a Desire to "let Obamacare fail", and the Trump administration has cut the ACA enrollment period in half and drastically reduced funding for advertising and other ways to encourage enrollment. The tax reform Trump signed into law at the end of his first year in office effectively repealed the individual health insurance mandate that was a major element of the Obamacare health insurance system; this repeal is scheduled to be implemented in 2019.