Ian MacKaye was born in Washington, D.C. on April 16, 1962, and grew up in the Glover Park neighborhood of Washington, D.C. His father was a writer for the "Washington Post", first as a White House reporter, then as a religion specialist; the senior MacKaye remains active with the socially progressive St. Stephen's Episcopal Church. In his capacities as a journalist in the White House Press Corps, MacKaye's father was in the presidential motorcade when John F. Kennedy was killed in 1963. Mackaye's paternal grandmother was Dorothy Cameron Disney Mackaye. She worked with Paul Popenoe on marriage advice columns and was a member of the Cosmopolitan Club. His grandfather was Milton MacKaye, also a magazine writer as well as an executive with the Office of War Information. According to MacKaye's longtime friend, singer Henry Rollins, MacKaye's parents "raised their kids in a tolerant, super-intellectual, open-minded atmosphere."