Hathcock was born in Little Rock, Arkansas on May 20, 1942. He grew up in rural Arkansas, living with his grandmother after his parents separated. He took to shooting and hunting at an early age, partly out of necessity to help feed his poor family. He would go into the woods with his dog and pretend to be a soldier and hunt imaginary Nazis in his "own little Germany". He hunted at that early age with a rifle that his father had brought back from Europe during World War II. Hathcock dreamed of being a Marine throughout his childhood, and so on May 20, 1959, at the age of 17, he enlisted in the Marine Corps. Hathcock married Jo Winstead on November 10, 1962.
Jo gave birth to a son, whom they named Carlos Norman Hathcock III. Before deploying to Vietnam, Hathcock had won shooting championships, including matches at Camp Perry and the Wimbledon Cup. In 1966 Hathcock started his deployment in Vietnam as an MP and later became a sniper after Captain Edward James Land pushed the Marines into raising snipers in every platoon. Land later recruited Marines who had set their own records in sharpshooting; he quickly found Hathcock, who had won the Wimbledon Cup, the most prestigious prize for long-range shooting, at Camp Perry in 1965.
During the Vietnam War Hathcock had 93 confirmed kills of North Vietnamese Army and Viet-Cong personnel.(During the Vietnam War, kills had to be confirmed by an acting third party, who had to be an officer, besides the sniper's spotter. Snipers often did not have an acting third party present, making confirmation difficult, especially if the target was behind enemy lines, as was usually the case.)
The North Vietnamese Army placed a bounty of $30,000 on Hathcock's life for killing so many of their men. Rewards put on U.S. snipers by the N.V.A. typically ranged from $8 to $2,000. Hathcock held the record for highest bounty and killed every Vietnamese marksman who sought it. The Viet Cong and N.V.A. called Hathcock Lông Trắng, translated as "White Feather", because of the white feather he kept in a band on his bush hat. After a platoon of trained Vietnamese snipers was sent to hunt down "White Feather", many Marines in the same area donned white feathers to deceive the enemy. These Marines were aware of the impact Hathcock's death would have and took it upon themselves to make themselves targets in order to confuse the counter-snipers.
One of Hathcock's most famous accomplishments was shooting an enemy sniper through the enemy's own rifle scope, hitting him in the eye and killing him. Hathcock and John Roland Burke, his spotter, were stalking the enemy sniper in the jungle near Hill 55, the firebase from which Hathcock was operating. The sniper, known only as the 'Cobra' had already killed several Marines and was believed to have been sent specifically to kill Hathcock. When Hathcock saw a flash of light (light reflecting off the enemy sniper's scope) in the bushes, he fired at it, shooting through the scope and killing the sniper. Surveying the situation, Hathcock concluded that the only feasible way he could have put the bullet straight down the enemy's scope and through his eye would have been if both snipers were zeroing in on each other at the same time and Hathcock fired first, which gave him only a few seconds to act. Given the flight time of rounds at long ranges, both snipers could have simultaneously killed one another. Hathcock took possession of the dead sniper's rifle, hoping to bring it home as a "trophy", but after tagging the rifle it was stolen from the armory.
A female Viet Cong sniper, platoon commander, and interrogator known as "Apache", because of her methods of torturing US Marines and ARVN troops and letting them bleed to death, was killed by Hathcock. This was a major morale victory as "Apache" was terrorizing the troops around Hill 55.
Hathcock only once removed the white feather from his bush hat while deployed in Vietnam. During a volunteer mission days before the end of his first deployment, he crawled over 1,500 yards of field to shoot an NVA commanding general. He was not informed of the details of the mission until he accepted it. This effort took four days and three nights, without sleep, of constant inch-by-inch crawling. Hathcock said he was almost stepped on as he lay camouflaged with grass and vegetation in a meadow shortly after sunset. At one point he was nearly bitten by a bamboo viper but had the presence of mind to avoid moving and giving up his position. As the general exited his tent, Hathcock fired a single shot that struck the general in the chest, killing him. He had to crawl back instead of run when soldiers started searching, and later regretted taking the mission, for in the aftermath of the assassination the NVA doubled their attacks in the area, apparently in retaliation for their general being killed and leading to an increase in American casualties.
After the arduous mission of killing the general, Hathcock returned to the United States in 1967.However, he missed the Marine Corps and returned to Vietnam in 1969, where he took command of a platoon of snipers.
Hathcock's career as a sniper came to a sudden end along Route 1, north of LZ Baldy in September 1969, when the amtrack he was riding on, an LVT-5, struck an anti-tank mine. Hathcock pulled seven Marines off the flame-engulfed vehicle and was severely burned before jumping to safety. While recovering, Hathcock received the Purple Heart. Nearly 30 years later, he would receive the Silver Star for this action. All eight injured marines were medevac-ed to the USS Repose (AH-16), then to a Naval Hospital in Tokyo, and ultimately to the burn center at Brooke Army Medical Center in San Antonio, Texas.
After returning to active duty, Hathcock helped establish the Marine Corps Scout Sniper School, at the Marine base in Quantico, Virginia. Due to his extreme injuries suffered in Vietnam, he was in nearly constant pain, but he continued to dedicate himself to teaching snipers. In 1975, Hathcock's health began to deteriorate, and he was diagnosed with multiple sclerosis. He stayed in the Corps, but his health continued to decline, and was forced to retire just 55 days short of the 20 years that would have made him eligible for full retirement pay. Being medically retired, he received 100% disability. He would have received only 50% of his final pay grade had he retired after 20 years. He fell into a state of depression when he was forced out of the Marines, because he felt as if the service had kicked him out. During this depression, his wife Jo nearly left him, but decided to stay. Hathcock eventually picked up the hobby of shark fishing, which helped him overcome his depression.
Hathcock provided sniper instruction to police departments and select military units, such as SEAL Team Six.
Hathcock once said that he survived in his work because of an ability to "get in the bubble", to put himself into a state of "utter, complete, absolute concentration", first with his equipment, then his environment, in which every breeze and every leaf meant something, and finally on his quarry. After the war, a friend showed Hathcock a passage written by Ernest Hemingway: "Certainly there is no hunting like the hunting of man, and those who have hunted armed men long enough and like it, never really care for anything else thereafter." He copied Hemingway's words on a piece of paper. "He got that right", Hathcock said. "It was the hunt, not the killing." Hathcock said in a book written about his career as a sniper: "I like shooting, and I love hunting. But I never did enjoy killing anybody. It's my job. If I don't get those bastards, then they're gonna kill a lot of these kids dressed up like Marines. That's the way I look at it."
Hathcock's son, Carlos Hathcock III, later enlisted in the Marine Corps; he retired from the Marine Corps as a Gunnery Sergeant after following in his father's footsteps as a shooter, and became a member of the Board of Governors of the Marine Corps Distinguished Shooters Association.
Carlos Hathcock died on February 23, 1999, in Virginia Beach, Virginia, after a long struggle with multiple sclerosis.