Lady and the Tramp is a 1955 American animated musical romantic comedy film produced by Walt Disney Productions and released by Buena Vista Film Distribution. Based on Ward Greene's 1945 Cosmopolitan magazine story "Happy Dan, the Cynical Dog", it was directed by Hamilton Luske, Clyde Geronimi, and Wilfred Jackson. Featuring the voices of Peggy Lee, Barbara Luddy, Larry Roberts, Bill Thompson, Bill Baucom, Stan Freberg, Verna Felton, Alan Reed, George Givot, Dallas McKennon, and Lee Millar, the film follows Lady, the pampered Cocker Spaniel, as she grows from puppy to adult, deals with changes in her family, and meets and falls in love with the homeless mutt Tramp.

Lady and the Tramp was released to theaters on June 22, 1955, to box office success. It was the first animated film to be filmed in the CinemaScope widescreen film process, as well as Disney's first animated film to be distributed by their Buena Vista division following their split from RKO Radio Pictures. It initially received generally mixed reviews by film critics, but critical reception for the film has been generally positive in modern times.

A direct-to-video sequel, titled Lady and the Tramp II: Scamp's Adventure, was released in 2001, and a live-action/CGI hybrid remake premiered in 2019 as a launch title for the Disney+ streaming service. In 2023, Lady and the Tramp was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically or aesthetically significant."