Iger is the son of Mimi (née Tunick) and Arthur L. Iger (b. 1926). His father was a World War II veteran who served as the Executive Vice President and General Manager of the Greenvale Marketing Corporation, and was also a Professor of Advertising and Public Relations. His mother worked at Boardman Junior High School in Oceanside. Arthur's father Joe (i.e. Robert's paternal grandfather) was Cartoonist Jerry Iger's brother.

Iger was born to a Jewish family in New York City. Iger was raised in the Long Island town of Oceanside, New York, where he attended the Fulton Avenue School and graduated from Oceanside High School in 1969. In 1973, he graduated magna cum laude from the Roy H. Park School of Communications at Ithaca College with a Bachelor of Science degree in Television and Radio.

Iger began his media career in 1972 as the host of “Campus Probe,” an Ithaca College television show. He dreamed of becoming a news anchor while he worked as a weatherman in Ithaca for five months, before shifting his career goals.

In 1974, Iger joined the American Broadcasting Company (ABC).

In 1989, Iger was named head of ABC Entertainment. He served as President of the ABC Network Television Group from January 1993 to 1994, while being appointed as Capital Cities/ABC Senior Vice President in March 1993 and Executive Vice President in July 1993.

In 1994, Iger was named President and Chief Operating Officer of ABC's corporate parent, Capital Cities/ABC.

In 1995, Iger married Willow Bay in an interfaith Jewish and Roman Catholic Service in Bridgehampton, New York. They have two children: Robert Maxwell "Max" Iger and william Iger.

In 1996, The Walt Disney Company purchased Capital Cities/ABC and renamed it ABC, Inc., where Iger remained President until 1999.

On February 25, 1999, Disney named Iger the President of Walt Disney International, the Business unit that oversees Disney's international operations, as well as Chairman of the ABC Group. Disney called the change a promotion for Iger. Some viewed this claim skeptically since Iger was being removed from day-to-day authority at the struggling ABC.

Disney named Iger the President and Chief Operating Officer (COO) on January 24, 2000, making him Disney's No. 2 executive under Chairman and CEO, Michael Eisner. Disney had been without a separate President since Eisner assumed the role following the departure of Michael Ovitz in 1997, after sixteen months at Disney.

Iger has been married twice. His first marriage to Kathleen Susan Iger ended in divorce. They had two children: Kathleen Pamela Iger and Amanda Iger. In 2005, Kathleen Pamela married Jarrod Alan Cushing in a civil ceremony at the Blithewold Mansion, Gardens and Arboretum in Rhode Island.

On January 24, 2006, under Iger’s leadership, Disney announced it would acquire Pixar for $7.4 billion in an all-stock transaction. In the same year, Iger also re-acquired the rights to Walt Disney's first star, Oswald the Lucky Rabbit, from NBCUniversal by releasing Sportscaster Al Michaels from ABC Sports to NBC Sports.

In August 2009, Iger spearheaded negotiations that led Disney to acquire Marvel Entertainment and its associated assets for $4 billion. As of August 2014, Disney has recouped over $4 billion at the box office through the Marvel movies.

On Tuesday November 15, 2011, Apple, Inc., now led by CEO Tim Cook after Steve Jobs's death, named Iger as a Director, and named Genentech Chairman Arthur Levinson, an Apple board member with a past membership on rival Google's board, as Jobs's replacement in the role of non-executive Chairman; both will serve on Apple's Audit Committee. Jobs had worked with Iger in the Pixar acquisition which had made Jobs the largest shareholder of Disney, and Iger licensed ABC shows to Apple for purchase through iTunes.

In June 2012, Steven Spielberg, founder of the USC Shoah Foundation Institute for Visual History and Education, presented Iger with the Ambassador for Humanity Award, the Institute's highest honor. Iger was recognized for his support of the Institute’s work, his longtime philanthropy, and his leadership role in corporate citizenship.

Iger was presented with The Milestone Award from the Producers Guild of America (PGA) in 2014. The award is the PGA’s highest recognition for an individual or team who has made historic contributions to entertainment.

In October 2015, the Toy Industry Association (TIA) inducted Iger into the Toy Industry Hall of Fame. He was selected by members of TIA in recognition of his significant contributions to the industry, and the impact his work has had on the lives of children worldwide.

In 2016, Iger switched his party registration from Democratic to independent (no party affiliation).

In December 2017, Disney was rumored to be negotiating with 21st Century Fox about acquiring many of their largest entertainment assets, including the 20th Century Fox film and TV studio, likely leaving Iger as CEO until the transition was made. On December 14, 2017, The Walt Disney Company agreed to acquire 21st Century Fox for $52.4 billion, requiring that Iger remain as CEO and chairman until 2021.

During Iger’s tenure, Disney broadened the company's roster of intellectual properties and its presence in international markets; Iger oversaw the acquisitions of Pixar in 2006 for $7.4 billion, Marvel Entertainment in 2009 for $4 billion, Lucasfilm in 2012 for $4.06 billion, and 21st Century Fox in 2017 for $52.4 billion, as well as the expansion of the company's theme park resorts in East Asia, with the introduction of Hong Kong Disneyland Resort and Shanghai Disney Resort in 2005 and 2016, respectively. Iger was also a driving force behind the reinvigoration of Walt Disney Animation Studios and the branded-release strategy of its film studio's output. Under Iger's control, Disney has experienced increases in revenue across its various divisions, with the company's market capitalization value increasing from $48.4 billion to $163 billion over a period of eleven years. As a result, Disney has been recognized as one of the "World's Most Reputable Companies" by Forbes (2006–2015), one of "America's Most Admired Companies" by Fortune Magazine (2009–2015), one of the “World's Most Respected Companies" by Barron’s (2009–2014), a “Best Place to Launch a Career” by BusinessWeek Magazine (2006–2010), and a "Company of the Year" by Yahoo Finance (2013).