Martin was born on August 14, 1945 in Waco, Texas, the son of Mary Lee (née Stewart; 1913–2002) and Glenn Vernon Martin (1914–1997), a real estate salesman and aspiring actor.He has an older sister, Melinda.
Martin is of English, Scottish, Welsh, Scots-Irish, German, and French descent, and was raised in Inglewood, California, with his sister, and then later in Garden Grove, California, in a Baptist family.
Martin was a cheerleader at Garden Grove High School. One of his earliest memories is of seeing his father, as an extra, serving drinks onstage at the Call Board Theatre on Melrose Place.
During World War II, in the United Kingdom, Martin’s father had appeared in a production of Our Town with Raymond Massey.
Expressing his affection through gifts, like cars and bikes, Martin’s father was stern, and not emotionally open to his son.He was proud but critical, with Martin later recalling that in his teens his feelings for his father were mostly of hatred
