[3] His paternal grandfather, P. J. Kennedy, served as a Massachusetts state legislator. Kennedy's maternal grandfather and namesake John F. Fitzgerald served as a U.S. Congressman and was elected to two terms as Mayor of Boston. All four of his grandparents were children of Irish immigrants.[1] Kennedy had an older brother, Joseph Jr., and seven younger siblings: Rosemary, Kathleen, Eunice, Patricia, Robert, Jean, and Edward.

Kennedy in a football uniform at Dexter School (Massachusetts), 1926
Kennedy lived in Brookline for the first ten years of his life. He attended the local St. Aidan's Church, where he was baptized on June 19, 1917.[4][5] He was educated through the 4th grade at the Edward Devotion School, the Noble and Greenough Lower School, and the Dexter School; all located in the Boston area. His earliest memories involved accompanying his grandfather Fitzgerald on walking tours of historic sites in Boston and discussions at the family dinner table about politics, sparking his interest in history and public service.[6][7][8] His father's business had kept him away from the family for long stretches of time, and his ventures were concentrated on Wall Street and Hollywood. 