His first role was on the sitcom Growing Pains, but his breakthrough film performance came in This Boy's Life. This was quickly followed by What's Eating Gilbert Grape; his performance as the mentally handicapped brother of Gilbert (Johnny Depp) brought him nominations for the Golden Globe and Academy Award for Best Supporting Actor. DiCaprio has also been nominated for two BAFTAs, three SAGs, and seven Golden Globes. He is a Golden Globe and a Silver Bear winner.

He gained fame for his role as Jack Dawson in Titanic, and has starred in many other successful films including Romeo + Juliet, Catch Me If You Can, and Blood Diamond, for which he was nominated for the Academy Award for Best Actor. Another Academy Award nomination came for his role as Howard Hughes in The Aviator, directed by Martin Scorsese. He has also worked with Scorsese in Gangs of New York, The Departed and Shutter Island.

DiCaprio was born in Los Angeles, California, the only child of a former legal secretary, and an underground comic artist and producer of comic books. His parents divorced when he was a year old and he lived mostly with his mother, although his father was around intermittently. During his childhood, DiCaprio was interested in baseball cards, comic books, and frequently visited museums with his father.

DiCaprio's career began with his appearing in several commercials and educational films. He got his break on television in 1990 when he was cast in the short-lived series based on the movie Parenthood. His debut film role was Critters 3, a B-grade horror film, which later went straight to video.

His breakthrough came in 1992, when he beat out hundreds of other boys for the role of Toby Wolff in This Boy's Life, co-starring Robert De Niro and Ellen Barkin. The move from "star" to "superstar" came when DiCaprio played Jack Dawson in the 1997 blockbuster Titanic, his popularity skyrocketed, with the media dubbing it "Leo-mania".

In 2002, DiCaprio starred in Gangs of New York (directed by Martin Scorsese) and Catch Me If You Can (directed by Steven Spielberg). Both films were very well received by critics. DiCaprio continued his run with Scorsese in the 2006 film The Departed as Billy Costigan, a smart undercover cop in Boston. His next film was Blood Diamond, released in December 2006.

In 2010, DiCaprio starred in Shutter Island directed by Martin Scorsese, which is based on the novel of the same name by Dennis Lehane.