Marty McFly is the world's second time traveler, the first to travel backwards in time and the first human to travel though time.
He was the youngest of three children to George and Lorraine Baines-McFly. He had a brother Dave who was born in 1963, sister Linda who was born in 1965 and girlfriend Jennifer Parker who was born in 1967.
His best friend is scientist Dr. Emmett Brown, whom Marty (and Jennifer) called "Doc" and referred to as "The Doc". There is a slight impression that Marty was somewhat embarrassed by his family and did not spend much time at home, preferring to hang out with Doc, Jennifer or the guys in his rock band, The Pinheads.