Robert De Niro was born in Greenwich Village, New York City, the son of Virginia Holton Admiral, a painter and poet, and Robert De Niro, Sr., an abstract expressionist painter and sculptor.

His father was of half Italian and half Irish descent, and his mother was of English, Irish, German, French, and Dutch ancestry. His Italian great-grandparents, Giovanni De Niro and Angelina Mercurio, emigrated from Ferrazzano, in the province of Campobasso, Molise; and his paternal grandmother, Helen O'Reilly, was the granddaughter of Edward O'Reilly, an immigrant from Ireland. De Niro's parents, who had met at the painting classes of Hans Hofmann in Provincetown (Cape Cod), Massachusetts, divorced when he was three years old. De Niro was raised by his mother in the Little Italy neighborhood of Manhattan, and in Greenwich Village. His father lived within walking distance and Robert spent much time with him as he was growing up.[7] De Niro attended PS 41, a public elementary school in Manhattan through the sixth grade, and then went to Elisabeth Irwin High School for seventh and eighth grades, the private upper school of the Little Red School House.[8] He was accepted at the High School of Music and Art for the ninth grade, but only attended for a short time before transferring to a public junior high school.[9] He began high school at the private McBurney School[10] and later attended the private Rhodes Preparatory School.

Although he never graduated from either.[12] Nicknamed "Bobby Milk" for his pallor, De Niro hung out with a group of street kids as a youth in Little Italy, some of whom have remained his lifelong friends.[13] The direction of his future had already been determined by his stage debut at age ten when he played the Cowardly Lion in a school production of The Wizard of Oz.[2][14] Along with finding relief from shyness through performing, De Niro was also entranced by the movies, and he dropped out of high school at age sixteen to pursue acting.[13] De Niro studied acting at the Stella Adler Conservatory, as well as Lee Strasberg's Actors Studio. In 1993, De Niro made his directorial debut with A Bronx Tale. The film, written by Chazz Palminteri, was about Palminteri's turbulent childhood in the Bronx. De Niro agreed to direct the film after seeing Palminteri's one-man off-Broadway play. De Niro also played Lorenzo, the bus driver who struggles to keep his son away from local mobster Sonny, played by Palminteri. De Niro did not direct another film until 2006's The Good Shepherd, which starred Matt Damon and Angelina Jolie. The Good Shepherd depicts the origins of the CIA, with Damon portraying one of the top counter-intelligence agents during World War II and the Cold War. De Niro has a small role as General Bill Sullivan, who recruits Damon's character into the world of counter-intelligence.

His father was of half Italian and half Irish descent, and his mother was of English, Irish, German, French, and Dutch ancestry. His Italian great-grandparents, Giovanni De Niro and Angelina Mercurio, emigrated from Ferrazzano, in the province of Campobasso, Molise; and his paternal grandmother, Helen O'Reilly, was the granddaughter of Edward O'Reilly, an immigrant from Ireland. De Niro's parents, who had met at the painting classes of Hans Hofmann in Provincetown (Cape Cod), Massachusetts, divorced when he was three years old. De Niro was raised by his mother in the Little Italy neighborhood of Manhattan, and in Greenwich Village. His father lived within walking distance and Robert spent much time with him as he was growing up. De Niro attended PS 41, a public elementary school in Manhattan through the sixth grade, and then went to Elisabeth Irwin High School for seventh and eighth grades, the private upper school of the Little Red School House. He was accepted at the High School of Music and Art for the ninth grade, but only attended for a short time before transferring to a public junior high school.[9] He began high school at the private McBurney School[10] and later attended the private Rhodes Preparatory School.

although he never graduated from either.[12] Nicknamed "Bobby Milk" for his pallor, De Niro hung out with a group of street kids as a youth in Little Italy, some of whom have remained his lifelong friends.[13] The direction of his future had already been determined by his stage debut at age ten when he played the Cowardly Lion in a school production of The Wizard of Oz.[2][14] Along with finding relief from shyness through performing, De Niro was also entranced by the movies, and he dropped out of high school at age sixteen to pursue acting.[13] De Niro studied acting at the Stella Adler Conservatory, as well as Lee Strasberg's Actors Studio. In 1993, De Niro made his directorial debut with A Bronx Tale. The film, written by Chazz Palminteri, was about Palminteri's turbulent childhood in the Bronx. De Niro agreed to direct the film after seeing Palminteri's one-man off-Broadway play. De Niro also played Lorenzo, the bus driver who struggles to keep his son away from local mobster Sonny, played by Palminteri.

De Niro's first movie role, in collaboration with Brian De Palma, was in 1963, at the age of 20, when he appeared opposite his friend Jill Clayburgh in The Wedding Party; however, the film was not released until 1969. He then played in Roger Corman's 1970 Bloody Mama, which starred Shelly Winters as Ma Barker. He gained popular attention with his role as a dying Major League Baseball player in Bang the Drum Slowly (1973).[2] That same year, he began his collaboration with Martin Scorsese, when he played the smalltime crook Johnny Boy, alongside Harvey Keitel's Charlie, in Mean Streets (1973).[2] In 1974, De Niro had a pivotal role in Francis Ford Coppola's The Godfather Part II, playing the young Vito Corleone – the director having remembered his previous auditions for the roles of Sonny Corleone, Michael Corleone, Carlo Rizzi and Paulie Gatto, in The Godfather. His performance earned him his first Academy Award, for Best Supporting Actor,[2] although Coppola accepted the award, as De Niro was not present at the Oscar ceremony. He became the first actor to win an Academy Award speaking mainly a foreign language, in this case, multiple Sicilian dialects[2] (although he delivered a few lines in English). De Niro and Marlon Brando, who played the older Vito Corleone in the first film, are the only actors to have won Oscars portraying the same fictional character. Brando and De Niro came together onscreen for the only time in The Score (2001).

Praised for his commitment to roles, stemming from his background in method acting, De Niro gained 60 pounds (27 kg) and learned how to box for his portrayal of Jake LaMotta in Raging Bull;[2] ground his teeth for Cape Fear; lived in Sicily for The Godfather Part II; worked as a cab driver for a few weeks for Taxi Driver;[35] and learned to play the saxophone for New York, New York. He again put on weight for his performance as Al Capone in The Untouchables (1987).[36] De Niro's brand of method acting includes employing whatever extreme tactic he feels is necessary to elicit the best performance from those with whom he is working. During the filming of The King of Comedy, for example, he directed a slew of anti-Semitic epithets at co-star Jerry Lewis in order to enhance and authenticate the anger demonstrated by his onscreen character. According to People magazine, the technique was successful. Lewis recalled, "I forgot the cameras were there... I was going for Bobby's throat."