Peter Sydney Lawford (September 7, 1923 – December 24, 1984) was an English actor, member of the "Rat Pack," and brother-in-law to President John F. Kennedy, perhaps more noted in later years for his off-screen activities as a celebrity than for his acting. In his earlier professional years (late 1930s through the 1950s) he had a strong presence in popular culture and starred in a number of highly acclaimed films.

Born in London, on September 7, 1923, the son of English World War I veteran Sir Sydney Turing Barlow Lawford and the former May Somerville Bunny, Peter Lawford spent his early childhood in France and began acting at a young age. Lawford's mother was said to have dressed him as a girl in private up until age eleven. Lady Lawford and Sir Sydney were not married when Peter was conceived. Young Peter lived all over the world with his parents. Because of his family's travels, Peter was never formally educated. His lack of education was allegedly a sore subject for the actor, which contributed to his feelings of inadequacy later on as a member of the Kennedy family, and throughout his adult life. In America, Sir Sydney and Lady Lawford were treated as royalty among the well-to-do in their new neighborhood of Palm Beach, Florida, and were always invited to events and social occasions. However, they lost whatever source of money they had when war was declared by the UK in 1939.

As a child Lawford severely injured his arm, in his words, "attempting to run through a glass door.". Doctors were able to save the arm, but the injury continued to bother him throughout his life, and the arm was slightly deformed. The injury was considered damaging enough to keep him from entering World War II, but this turn of fate was probably the greatest boon to his career. At that time, Hollywood was infatuated with heroic Englishmen, and as war movies were being churned out by the dozens and American actors volunteered or were drafted for the war, Lawford put his talents to work "stateside".