Wallace was born in St. Mary's Hospital in the Brooklyn borough of New York City, on May 21, 1972, as the only child of Jamaican parents, Voletta Wallace, a preschool Teacher, and Selwyn George Latore, a welder and Politician. His father left the family when Wallace was two years old, and his mother worked two jobs while raising him. Wallace grew up in Clinton Hill, on 226 St. James Place, near the border of Bedford-Stuyvesant, Brooklyn.

Wallace began rapping when he was a teenager. He entertained people on the streets and performed with local groups the Old Gold Brothers and the Techniques. After being released from jail, Wallace made a demo tape under the name Biggie Smalls, a reference to a character in the 1975 film Let's Do It Again as well as his stature; he stood at 6 feet 3 inches (1.91 m) and weighed 300 to 380 lb (140–170 kg) according to differing accounts. The tape was reportedly made with no serious intent of getting a recording deal. However, it was promoted by New York-based DJ Mister Cee, who had previously worked with Big Daddy Kane, and it was heard by the Editor of The Source.

At his request, Wallace transferred out of Bishop Loughlin Memorial High School to attend George Westinghouse Career and Technical Education High School, which Future Rappers DMX, Jay-Z and Busta Rhymes also attended at the time. According to his mother, Wallace was still a good student, but he developed a "smart-ass" attitude at the new school. At age seventeen, Wallace dropped out of school and became further involved in crime. In 1989, he was arrested on weapons charges in Brooklyn and sentenced to five years' probation. In 1990, he was arrested on a violation of his probation. A year later, Wallace was arrested in North Carolina for dealing crack cocaine. He spent nine months in jail before making bail.

In March 1992, Wallace was featured in The Source's Unsigned Hype column, dedicated to aspiring Rappers, and made a recording off the back of this success. The demo tape was heard by Uptown Records A&R and record Producer Sean Combs, who arranged for a meeting with Wallace. He was signed to Uptown immediately and made an appearance on label mates, Heavy D & the Boyz' "A Buncha Niggas" (from the album Blue Funk). Soon after signing his recording contract, Combs was fired from Uptown and started a new label. Wallace followed and in mid-1992, signed to Combs' new imprint label, Bad Boy Records.

Later in the year, Wallace gained exposure on a remix to Mary J. Blige's single "Real Love", under the pseudonym The Notorious B.I.G. He recorded under this name for the remainder of his career, after finding the original moniker "Biggie Smalls" was already in use. "Real Love" peaked at No. 7 on the Billboard Hot 100 chart and was followed by a remix of Blige's "What's the 411?". He continued this success, to a lesser extent, on remixes with Neneh Cherry ("Buddy X") and reggae Artist Super Cat ("Dolly My Baby", also featuring Combs) in 1993. In April 1993, his solo track, "Party and Bullshit", appeared on the Who's the Man? Soundtrack. In July 1994, he appeared alongside LL Cool J and Busta Rhymes on a remix to label mate Craig Mack's "Flava in Ya Ear", reaching No. 9 on the Billboard Hot 100.

Allmusic wrote that the success of Ready to Die is "mostly due to Wallace's skill as a storyteller"; in 1994, Rolling Stone described Wallace's ability in this technique as painting "a sonic picture so vibrant that you're transported right to the scene". On Life After Death Wallace notably demonstrated this skill on "I Got a Story to Tell", creating a story as a rap for the first half of the song and then retelling the same story "for his boys" in conversation form.

Wallace began recording his second studio album in September 1995. The album, recorded in New York City, Trinidad, and Los Angeles, was interrupted during its 18 months of creation by injury, legal wranglings and the highly publicized hip hop dispute in which he was involved. During this time, he also worked with R&B/pop singer, Songwriter and Producer Michael Jackson for the HIStory album. Lil' Cease claimed in 2013 that Wallace denied his wishes to meet Jackson, citing that he did not "trust Michael with kids".

On October 29, 1996, Faith Evans gave birth to Wallace's son, Christopher "C.J." Wallace, Jr. The following month, Junior M.A.F.I.A. member Lil' Kim released her debut album, Hard Core, under Wallace's direction while the two were having a "love affair". Lil' Kim recalled being Wallace's "biggest fan" and her being "his pride and joy." In a 2012 interview, Lil' Kim said Wallace prevented her from doing a remix of the Jodeci single "Love U 4 Life" by locking her in a room and according to her, Wallace stated that she was not "gonna go do no song with them," likely because of the group's close affiliation with Tupac and Death Row Records.

In mid-1997, Combs released his debut album, No Way Out, which featured Wallace on five songs, notably on the third single "Victory". The most prominent single from the record album was "I'll Be Missing You", featuring Combs, Faith Evans and 112, which was dedicated to Wallace's memory. At the 1998 Grammy Awards, Life After Death and its first two singles received nominations in the rap category. The album award was won by Combs' No Way Out and "I'll Be Missing You" won the award in the category of Best Rap Performance By A Duo Or Group in which "Mo Money Mo Problems" was nominated.

In December 1999, Bad Boy released Born Again. The album consisted of previously unreleased material mixed with guest appearances including many artists Wallace had never collaborated with in his lifetime. It gained some positive reviews but received criticism for its unlikely pairings; The Source describing it as "compiling some of the most awkward collaborations of his career". Nevertheless, the album sold 2 million copies. Wallace appeared on Michael Jackson's 2001 album, Invincible. Over the course of time, his vocals were heard on hit songs such as "Foolish" by Ashanti and "Realest Niggas" in 2002, and the song "Runnin' (Dying to Live)" with Shakur the following year. In 2005, Duets: The Final Chapter continued the pattern started on Born Again, criticized for the lack of significant vocals by Wallace on some of its songs. Its lead single "Nasty Girl" became Wallace's first UK No. 1 single. Combs and Voletta Wallace have stated the album will be the last release primarily featuring new material.

Sixteen days after his death, Wallace's double-disc second album was released as planned with the shortened title of Life After Death and hit No. 1 on the Billboard 200 charts, after making a premature appearance at No. 176 due to street-date violations. The record album featured a much wider range of guests and producers than its predecessor. It gained strong reviews and in 2000 was certified Diamond, the highest RIAA certification awarded to a solo hip hop album.

Considered one of the best artists in hip hop music, Wallace was described by AllMusic as "the savior of East Coast hip-hop". The Source magazine named Wallace the greatest Rapper of all time in its 150th issue in 2002. In 2003, when XXL magazine asked several hip hop artists to list their five favorite MCs, Wallace's name appeared on more rappers' lists than anyone else. In 2006, MTV ranked him at No. 3 on their list of The Greatest MCs of All Time, calling him possibly "the most skillful ever on the mic". Editors of About.com ranked him No. 3 on their list of the Top 50 MCs of Our Time (1987–2007). In 2012, The Source ranked him No. 3 on their list of the Top 50 Lyrical Leaders of all time. Rolling Stone has referred to him as the "greatest Rapper that ever lived". In 2015, Billboard named Wallace as the greatest Rapper of all time.

Wallace had begun to promote a clothing line called Brooklyn Mint, which was to produce plus-sized clothing but fell dormant after he died. In 2004, his managers, Mark Pitts and Wayne Barrow, launched the clothing line, with help from Jay-Z, selling T-shirts with images of Wallace on them. A portion of the proceeds go to the Christopher Wallace Foundation and to Jay-Z's Shawn Carter Scholarship Foundation. In 2005, Voletta Wallace hired branding and licensing agency Wicked Cow Entertainment to guide the estate's licensing efforts. Wallace-branded products on the market include action figures, blankets, and cell phone content.

Since his death, Wallace's lyrics have been sampled and quoted by a variety of hip hop, R&B and pop artists including Jay-Z, 50 Cent, Alicia Keys, Fat Joe, Nelly, Ja Rule, Eminem, Lil Wayne, Game, Clinton Sparks, Michael Jackson and Usher. On August 28, 2005, at the 2005 MTV Video Music Awards, Sean Combs (then using the rap alias "P. Diddy") and Snoop Dogg paid tribute to Wallace: an orchestra played while the vocals from "Juicy" and "Warning" played on the arena speakers. In September 2005, VH1 held its second annual "Hip Hop Honors", with a tribute to Wallace headlining the show.

In early October 2007, open casting calls for the role of Wallace began. Actors, Rappers and unknowns all tried out. Beanie Sigel auditioned for the role, but was not picked. Sean Kingston claimed that he would play the role of Wallace, but producers denied it. Eventually it was announced that Rapper Jamal Woolard was chosen to play Wallace while Wallace's son, Christopher Wallace, Jr. was cast to play Wallace as a child. Other cast members include Angela Bassett as Voletta Wallace, Derek Luke as Sean Combs, Antonique Smith as Faith Evans, Naturi Naughton formerly of 3LW as Lil' Kim, and Anthony Mackie as Tupac Shakur. Bad Boy released a Soundtrack album to the film on January 13, 2009; the album contains hit singles of B.I.G. such as "Hypnotize", "Juicy", and "Warning" as well as rarities.

In 2011 The FBI released hundreds of pages of records (heavily redacted) of their investigation into the 1997 slaying. As part of the release, the FBI released a detailed list to items Biggie had in his pockets the night he was murdered.The FBI list Biggie's Pocket contents as: a Georgia driver’s license, a pen, 0.91 grams of marijuana, an asthma inhaler, and three condoms among his possessions. At the time of his death it was well known the Badboy Records camp had taken residence in Atlanta Georgia which is the reason why Notorious BIG maintained a Georgia Drivers License. Badboy Records Atlanta residency is also evident with Diddy's relationship with BIG Meech, the opening of the first Justin's Restaurant in Atlanta, and eventually Mase quitting rap and becoming a Pastor in Atlanta Georgia.

Lateef of Latyrx notes that Wallace had, "intense and complex flows", Fredro Starr of Onyx says, "Biggie was a master of the flow", and Bishop Lamont states that Wallace mastered "all the hemispheres of the music". "Notorious B.I.G. also often used the single-line rhyme scheme to add variety and interest to his flow". Big Daddy Kane suggests that Wallace didn't need a large vocabulary to impress listeners – "he just put his words together a slick way and it worked real good for him". Wallace was known to compose lyrics in his head, rather than write them down on paper, in a similar way to Jay-Z.

Busta Rhymes claimed to have seen Wallace giving out free copies of Ready to Die from his home, which Rhymes reasoned as "his way of marketing himself." Around the time of the album's release, Wallace became friends with Tupac Shakur, also a Rapper. Cousin Lil' Cease recalled the pair being close, often traveling together whenever they were not active in furthering their careers. According to him, Wallace was a frequent guest at Shakur's home and they constantly spent time together when Shakur was in California or Washington, D.C.. It was claimed by Yukmouth, an Oakland emcee, that Wallace's style was inspired by that of Shakur. Wallace also formed a friendship with Shaquille O'Neal, O'Neal remembering his first time hearing Wallace, during listening to the song "Gimme the Loot", where Wallace mentioned him in the lyrics and thereby attracted O'Neal to his music. O'Neal requested a collaboration with Wallace, which resulted in the song "You Can't Stop the Reign". Sean Combs related that Wallace would not do collaborations with "anybody he didn't really respect", adding that Wallace paid O'Neal "respect by shouting him out." Daz Dillinger said in 2015 that Wallace and he were "cool". Wallace would travel to meet with him, and Dillinger recalled serving him cannabis and recording two songs with him.

A duet album titled The King & I, featuring Evans and Notorious B.I.G., was released on May 19, 2017, following the two singles "NYC", featuring Jadakiss, and "When We Party", featuring Snoop Dogg.

Moreover, Philips' article was based on multiple sources. As the Assistant Managing Editor of the LA Times Mark Duvoisin wrote: "Philips' story has withstood all challenges to its accuracy, ...[and] remains the definitive account of the Shakur slaying." Faith Evans remembered her husband calling her the night of Shakur's death and crying due to him being in shock. Evans added, "I think it’s fair to say he was probably afraid, given everything that was going on at that time and all the hype that was put on this so-called beef that he didn’t really have in his heart against anyone." Wayne Barrow, Wallace's co-manager at the time, said Wallace was recording the song "Nasty Girl" the night Shakur was shot. Shortly after Shakur's death, he met with Snoop Dogg, who claimed that Wallace played the song "Somebody Gotta Die" for him, in which Snoop Dogg was mentioned, and declared he never hated Shakur.