His real name is Clinton Francis "Clint" Barton, and was orphaned at an early age when his parents died in a car accident and was sent to a children's home with his brother Bernard. He and his brother ran away to join the Carson Carnival of Traveling Wonders, and the pair worked as roustabouts. While a member of the circus, Hawkeye was trained by the original Swordsman (Jacques Duquesne) and Trickshot. Clint's life, however, would forever be changed after he stumbled onto the Swordsman counting the money he had just robbed from the carnival. The Swordsman offered Clint to become his partner in crime, but Clint rejected his mentor, sparking a fight that ended when the Swordsman left him for dead after he fell from the high wire. Barney, too, abandoned him, in disbelief that Clint passed up such an opportunity. Trickshot stepped up his role as Clint's mentor, later asking him to join him in raiding a criminal named Marko. However, Clint severely injured one of Marko's guards and discovered him to be his brother, Barney. Repelled by the consequences of his actions (and his mentor's role in prompting them), he abandoned Trickshot and parted on bad terms.

His natural archery abilities honed to an expert level, Clint wandered the country, working in various carnivals or otherwise making money out of the costume and persona of "Hawkeye". One day, when witnessing Iron Man save the lives of some people at the carnival, he decided to become a costumed crime-fighter himself. But as luck would have it, on Hawkeye's first night on patrol, he was mistaken for a criminal by the police and hunted down.He soon met the Black Widow, who was working at the time as a costumed villain for her country, and she easily seduced the hot-headed adventurer, making him think it was in his interest to defeat Iron Man. He attempted to do so according to her prompting on several occasions, but soon wised up, regretting his decision. Instead, he hoped to join Iron Man's team of Avenger

He has no special power. As Goliath, Barton used gases designed by Hank Pym to grow to great heights, with appropriate increases in strength and toughness. Hawkeye is a world-class archer and marksman. His above average reflexes and hand-eye-coordination make him the most proficient archer ever known. He is also trained to throw knifes, darts, balls, bolas and boomerangs. He is natural athlete. He is also formidable unarmed combatant, thanks largely for longtime combat training with Captain America. He also has extensive training as an acrobat and aerialist.