Clint Barton 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 Avengers. As a way of proving himself, he broke into the Avengers Mansion and convinced their butler, Jarvis, to play the role of a victim so he could display his powers. Iron Man vouched for Hawkeye, and he joined the new line-up that included Captain America, the Scarlet Witch, and Quicksilver.

Hawkeye stayed with the Avengers for a long time, leaving only briefly when his temper and ego led him to believe he wasn't wanted. He returned after a short period, having joined the "non-team" Defenders in the meantime. At one point, Hawkeye was passed over accompanying the Avengers in theKree-Skrull War due to his lack of superhuman abilities. Not one to be deterred so easily, Hawkeye took on the identity of Goliath with the use of Hank Pym's size-altering particles. He hitched a ride so as to join the team in their intergalactic adventure and maintained the Goliath identity for several months upon their return to Earth.

During his time as Goliath, Clint was approached by his brother, who had become a big-time racketeer. Barney had learned of Egghead's plans to construct an orbiting laser death-ray to extort money from the United States and came to the Avengers for help. The Avengers confronted Egghead and his allies, the Mad Thinker and the Puppet Master, but tragically, Barney died in the ensuing battle. Later, Egghead would use the Swordsman to capture Clint as Goliath, thinking him to be Hank Pym, but Hawkeye-as-Goliath soon defeated both criminals, avenging his brother at last. Soon afterward, Clint abandoned the Goliath identity but continued to serve the Avengers as Hawkeye the Marksman.

Another leave of absence was forced upon him, when, due to a type of "affirmative action", he was replaced by the Falcon to comply with the Avengers' government sanction. During this time, he eventually found employment as a night security guard for Cross Technological Enterprises (CTE). Never gone from his team for long, he soon rejoined the fold, although one particular solo adventure would have a lasting impact. His boss, head of CTE, was the villain known as Crossfire and hoped to test his ultrasonic equipment with which he hoped to turn heroes against one another, With the help of the ex-secret agent, Mockingbird, Hawkeye defeated Crossfire. The two heroes, head over heels in love, promptly got married.

At the time, the Vision was expanding the Avengers' operations, and he named Hawkeye chairman of a west coast branch of Avengers, and Mockingbird joined him as a charter member. Hawkeye led the team through several adventures, growing into a competent leader.

He even had time to embark on a series of solo adventures. During one of these latter adventures, Hawkeye had to defend himself against many costumed mercenaries and villains hoping to collect a bounty placed on his right arm. The mastermind behind it all proved to be Trickshot, now dying of cancer, and he was hoping to goad Hawkeye into killing him. Instead, Hawkeye reconciled with his former mentor and friend.

During an adventure where the team became lost in the past, his wife was involved with the death of the Old West hero, the Phantom Rider, and the situation caused the couple to split up.

Shortly after, the government forced the membership of the U.S.Agent on the team, and Hawkeye quit. Both he and Mockingbird wound up investigating and leading the heroes known as the Great Lakes Avengers. Eventually, however, Hawkeye left the Midwest to rejoin the Avengers West Coast, although he never really led the team again.

Hawkeye continued to adventure with the team, even alongside his separated wife, and was present with them when Mockingbird was killed in a demonic dimension, saving her husband's life from an attack by Mephisto.

Eventually drawn back to the Avengers' fold when the team was attacked in a plan orchestrated by Immortus, Hawkeye was present with the team when they apparently died, sacrificing themselves to absorb the energies of Onslaught. Eventually, Hawkeye and the other heroes were restored, and Hawkeye quickly rejoined the reforming Avengers.

However, Hawkeye was dissatisfied. His previous experience as a team leader left him feeling too anxious as a regular member. Hawkeye turned his attention instead to the team of reforming villains, the Thunderbolts. Sympathetic because of his own outlaw past and eager for new challenges, Hawkeye offered to serve as the Thunderbolts' new leader if they would continue fighting crime and remain reformed. During his stint as their leader, he became a friend and mentor to the group, honing their skills and greatly enhancing their reputations. He and his teammate Moonstone had even began developing romantic inclinations. The Thunderbolts soon became trusted allies of the Avengers, though Hawkeye formally resigned his membership in the latter group since he didn't want any perceived criminal association with the Thunderbolts to negatively impact the Avengers.

Hawkeye returned to the Avengers full-time. At one point, he and the Wasp had a dallying romance, upsetting Yellowjacket, and the two heroes avoided talking about the uncomfortable situation. Soon afterwards, however, the Avengers suffered a series of sudden and devastating attacks from friends and enemies alike, culminating in a surprise attack by the alien Kree. During the Kree invasion, Hawkeye suffered a mortal shot to the back. In his dying moments, Hawkeye overpowered a Kree soldier, using the soldier's jetpack to fly both of them into the Kree's command ship. Hawkeye sacrificed his life to single-handedly thwart the invasion. (These attacks were in part motivated by the Scarlet Witch, whose mind became unhinged with the magical powers she constantly felt forced to control, and it is believed the Kree invasion was all a magical construct of the Scarlet Witch.)

Hawkeye showed up alive once more in the Scarlet Witch's mutant-dominated alternate reality, with no memory of the reality before. When a young mutant gave several of the heroes the ability to remember the way the world once was, Clint and the others were horrified at what the Scarlet Witch had done.

With his memory restored, Hawkeye remembered the events his own death. When the heroes confronted the Witch and her children, Hawkeye angrily shot her in the back, demanding to know why she had killed him, as he was her friend and had only love for her. One of the Witch's children made Hawkeye vanish into nothingness with just a thought. After reality was restored several heroes arrived at the ruined Avenger's Mansion after a report that someone had been there, only to find Clint's costume and a newspaper cutting about his death, pinned to the ruins by Hawkeye's trademark purple arrows.

It was later revealed that Clint indeed survived and that he was the one who nailed the costume on the wall. He realized that the whole world thought that he was dead and he himself also had doubts of who he really was. In his disordered state of mind he found himself standing in front of Doctor Strange's house. He met Strange who ensured him that he was who he thinks he is and that he is indeed alive. Strange informed him of what had happened and that Wanda couldn't be found and that he thought she might be dead. Clint didn't believe this and started to search for her. He found her in Wundagore Mountain where she lived with her aunt Agatha. She didn't remember anything and didn't recognize him at all. She also told him that she had lived her whole life in that village.

Clint decided to stay in the village for some time with her until he for some reason came back to the states and contacted Iron Man revealing to him that he was alive. After Iron Man had ensured that he was who he said he was he made Clint an offer to be the next Captain America. Clint even tried the flag on and got to use the original shield but he realized that it was a mistake when he met Patriot and new Hawkeye who convinced that he wasn't Captain America. Clint let them escape and gave the shield back to Iron Man and told him that he will mail the "flag" later.

Not long after this Clint again found himself in front of Doctor Strange's house now seeming as though it had been abandoned and sold to a franchise company. In reality, however, it was illusion cast by Strange to hide himself and his team members from Iron Man. They decided to show themselves to Clint and after some talk and magic they decided to give Clint Ronin's costume. They then left to Japan to save their team member Maya Lopez from the Hand.

After an alien Skrull ship crashes in the Savage Land, Clint battles and kills a Skrull impersonating Mockingbird and himself. He is later reunited with the real Mockingbird during a final battle with the Skrulls. And though the two fought about their past at first, they eventually started their relationship once more.

While Clint and his wife join up with the New Avengers to search for Luke Cage's daughter, Norman Osborn forms the Dark Avengers with villains assuming the identities of fugitive heroes; Bullseye assumes the identity of Hawkeye. Clint is very much infuriated that those who would exploit their good names take advantage of the invasion. He doesn't even want to wait for the Dark Avengers to show their true colors and wants to fight them immediately. After a failed attempt to lure the Dark Avengers into a battle turns instead into a fight with the Hood's crime syndicate, Clint goes on television, unmasked, and publicly denounces the Dark Avengers, stating that Osborn has formed an alliance with the Hood, and urging people to fight against his new regime. When Norman Osborn declares war on the X-Men that reside in Utopia; Clint remarks to the other New Avengers that he is going to kill Norman. With no one backing him Clint assaults Avenger Tower on his own; only to fail and get arrested by Osborn. Eventually Clint is freed by his fellow team-mates, but not before being tortured by Osbourne.

After the Siege of Asgard, Clint is part of the new heroic age of heroes and he remains as part of Steve Roger's main team of Avengers.