During WWII, Lancaster joined the United States Army and performed with the USO. Though initially unenthusiastic about acting, he returned from service, auditioned for a Broadway play and was offered a role. Though the play was not successful, Lancaster's performance drew the attention of a Hollywood agent who had him cast in the 1946 motion picture The Killers. The muscular, 6'2" actor won significant acclaim and appeared in two more films the following year. Subsequently, he played in a variety of movies, but especially in dramas, thrillers, military and adventure films. In two of the adventures, The Flame and the Arrow and The Crimson Pirate, a friend from his circus years, Nick Cravat, played a leading role, and both actors impressed audiences with their acrobatic prowess. In the mid '50s, Lancaster went on challenging himself with varied cinematic roles, and satisfied longtime aspirations by moving into film producing as well. In most of his roles, whether in drama, circus, western or other genres, the self-taught actor was successful; he evolved into a solid and versatile performer and eventually a superstar. His work was recognized in 1960 when he won the Academy Award for Best Actor, a Golden Globe Award, and the New York Film Critics Award for his performance in Elmer Gantry.

During the latter part of his career, Lancaster left adventure and acrobatic movies behind and portrayed distinguished characters, earning himself ever greater prestige among directors and audiences alike. This period brought him work on several European productions with directors including Luchino Visconti and Bernardo Bertolucci. Lancaster sought demanding roles and, if he liked a part or a director, was prepared to work for much lower pay than he might have earned elsewhere; he even helped to finance movies in whose artistic value he believed. He produced a number of films himself and also mentored such new directors as Sydney Pollack and John Frankenheimer, thus adding to his numerous acting achievements a pioneering role the development of independent cinema. He also appeared in several TV films.

For his contribution to the motion picture industry, Burt Lancaster has a star on the Hollywood Walk of Fame at 6801 Hollywood Blvd.

He was also an unabashed liberal activist and spoke out many times in support of minorities and forming liberal groups.

As famous for his prickly, temparamental personality as much as he was for his skills at blending into and out of different characterizations, Lancaster vigorously guarded his private life. He was married three times and had five children. His first spouse, from 1935 to 1946, was June Ernst, from whom he divorced. His second marriage was with Norma Anderson from 1946 to 1969 and also ended in divorce. His third wife was Susan Martin, whom he married in 1991. As Mr. Lancaster aged, heart trouble increasingly hindered him from working as intensely as his passion and determination demanded. Following two minor heart attacks he had to undergo an emergency quadruple heart bypass in 1983, after which he was in frail health. A massive cerebral stroke in 1990 left him in a wheel-chair, partly paralyzed and unable to speak properly. At home in Los Angeles on October 20, 1994, Burt Lancaster died of a heart attack at the age of 80.