Haynesworth was born in Hartsville, South Carolina. He attended Hartsville High School, and participated in football, track, and shot put. Haynesworth accounted for 150 tackles, 56 tackles for loss, six sacks, and six fumble recoveries as a junior; he followed that by tallying 110 tackles, 51 quarterback pressures, and six sacks as a senior in 1998.

As a student-athlete at the University of Tennessee, Haynesworth was a three-year letterman for the Tennessee Volunteers football team under head coach Phillip Fulmer. He lined up at the right defensive tackle position next to John Henderson. He compiled 66 tackles, five sacks, 31 quarterback pressures, 20 tackles for a loss, and nine pass deflections during his collegiate career. He earned Sporting News Freshman All-American honors in 1999 and was named Second Team All-Southeastern Conference after his junior season.

Considered “potentially a brutal run-stopper” by The New York Times, Haynesworth was selected by the Tennessee Titans in the first round with the 15th overall pick in the 2002 NFL Draft. He was the fourth defensive tackle selected from a draft class considered to be loaded with talented defensive linemen. At Tennessee’s Pro Day in 2002, when he was 20 years old, Haynesworth measured at 6-feet-6 and 317 pounds, ran a 4.82 40-yard dash, and had a 39-inch vertical jump and a 9-foot, 7-inch broad jump. He did not work out at the 2002 NFL Combine.

An incident foreshadowing future incidents with Haynesworth occurred at a Titans training camp in 2003, where Haynesworth kicked his former teammate, center Justin Hartwig, in the chest, then had to be restrained by other teammates.

On October 1, 2006, in the third quarter of a game against the Dallas Cowboys, running back Julius Jones scored on a rushing play. Center Andre Gurode fell to the ground, and his helmet was removed by Haynesworth. Haynesworth attempted to stomp on Gurode’s head, but missed. A second stomp opened a severe wound on Gurode’s forehead, narrowly missing his right eye. Referee Jerome Boger assessed Haynesworth a 15-yard unsportsmanlike conduct penalty, to which Haynesworth protested by taking off his helmet and throwing it into the turf; Haynesworth was then assessed an additional 15-yard penalty and ejected from the game.

On October 2, 2006, Haynesworth was suspended for five games without pay by the NFL. The suspension was only the second multi-game suspension in NFL history for an on-the-field incident, more than twice as long as the previous longest suspension, given in 1986 by then-commissioner Pete Rozelle to Green Bay nose tackle Charles Martin. Based on his 2006 base salary of $646,251, Haynesworth forfeited more than $190,000 in salary. Roger Goodell, who had recently become NFL’s commissioner in the past month, stated that there was “absolutely no place in the game, or anywhere else” for Haynesworth’s behavior. However, ESPN’s Mark Schlereth, a 12-year NFL veteran, felt that Haynesworth should have been suspended for the rest of the season. Haynesworth’s suspension was the longest for an in-game incident in NFL history until it was surpassed by Vontaze Burfict, who was suspended 12 games plus the 2019 playoffs for repeated violations of helmet hit rules.

Arrest warrants were issued against Haynesworth in two Tennessee counties in May 2006 stemming from a traffic incident on Interstate 40. Both sets of charges were dropped in June 2006. The judge in the Putnam County case tossed the charges on the grounds that the alleged offense happened out of their jurisdiction. In Smith County, the district attorney dismissed the charges. In March 2009, Haynesworth was indicted on two misdemeanor traffic charges stemming from a December 2008 car accident in Tennessee. In an accident on Interstate 65, Corey Edmonson was partially paralyzed after colliding with Haynesworth’s car. Haynesworth was driving his Ferrari at speeds in excess of 100 mph when he struck Edmonson’s vehicle, which struck a concrete barrier.

On September 9, 2007, in the season opener against the Jacksonville Jaguars, Haynesworth was called for unnecessary roughness when he slammed running back Maurice Jones-Drew to the ground after a tackle. He was fined $5,000 by the NFL for this incident. Afterwards, when asked if he would be gentler during play, he commented, “I’m not going to be any gentler or whatever. Maybe I’ll just help them up.”

An unrestricted free agent in the 2009 off-season, Haynesworth signed a seven-year, $100 million contract with the Washington Redskins on the first day of free agency, February 27, 2009. This was despite being offered more money by the Tampa Bay Buccaneers. The deal was expected to pay Haynesworth $32 million in the first 13 months, included $41 million guaranteed, and could have reached $115 million if all incentives were met. Tennessee’s final offer to Haynesworth reportedly amounted to a four-year package worth $34 million total, with about $20 million in guarantees. Haynesworth reported on SIRIUS Blitz that the Tampa Bay Buccaneers offered him a $120 million deal that could potentially increase by 20%. He says that he took a discount to play with the Redskins because of their large fan base and media outlet, something that he also did not have in Tennessee. In April 2009, the Titans asked the NFL to consider tampering charges against the Redskins, claiming that the Redskins contacted Haynesworth before the free agency period began on February 27.

From the beginning of his time with the Redskins, Haynesworth presented problems for the coaching staff. He refused to participate in off-season workouts, and arrived at camp in poor physical condition, unable to pass a basic fitness test. He also made it clear that he did not like to play nose tackle in the team’s 3–4 defensive scheme, having played in a 4–3 scheme in Tennessee. After a 45–12 loss to the New York Giants on Monday Night Football in 2009, Haynesworth questioned the scheme of defensive coordinator Greg Blache, and stated that he could not “survive another season in this system if it stays the way it is.”

On December 7, 2010, it was announced that Haynesworth would spend the rest of the season on the restricted list. There had been conflicts throughout the 2010 preseason with Haynesworth and the coaching staff. After a dispute over his absence at a practice in which Haynesworth claimed to be ill, the team suspended him for “conduct detrimental to the club”. Head coach Mike Shanahan said the suspension followed a refusal by Haynesworth to cooperate in a variety of ways and not only because of the practice absence.

During the 2010 season, Haynesworth had a career-low 13 tackles and just 2.5 sacks in eight games, leading the NFL Network to name the signing of Haynesworth as the “worst free-agency move of the last decade.” Many other NFL writers have gone further, calling Haynesworth the worst free agent bust in NFL history. Haynesworth created some controversy in March 2015 when he likened Ndamukong Suh’s six-year, $114 million contract to his previous contract with the Redskins.

On June 22, 2010, it was reported that Clayton Bank & Trust was suing the NFL lineman, alleging that Haynesworth had failed to make payments on a loan in the amount of more than $2.38 million. The suit was filed in the Knox County Chancery Court on June 18, 2010. According to papers, Haynesworth entered a commercial loan agreement for the original principal amount of $2,381,688.58 on June 27, 2009. On February 27, 2009, the two parties entered into an Extension Agreement with an effective date of February 27, 2010, according to the suit. The attorney for Clayton Bank & Trust, Hugh B. Ward, Jr., was seeking a little over $2.4 million.

In 2010, Silvia Mena, a stripper from New York, claimed in a $10 million lawsuit that Haynesworth impregnated her and left her with no financial assistance.

In a response to Haynesworth’s failure to pass the Redskins’ conditioning test in July 2010, the edition of August 27, 2010 of satire news organization The Onion ran the headline (with an accompanying photo), “Report: Albert Haynesworth Just A Mound Of Ice Cream And Hot Dogs.”

Haynesworth was traded to the New England Patriots on July 28, 2011, for a fifth-round draft pick in the 2013 NFL Draft. He lasted less than four months with the Patriots, and on November 8, 2011, Haynesworth was placed on waivers. His placement on waivers came days after he got into a confrontation with assistant Pepper Johnson on the sidelines.

In 2011, Haynesworth allegedly threw a punch to the nose of Joel Velazques, 38, of Leesburg, Virginia during a traffic altercation.

Two days after being released by the Patriots, Haynesworth was claimed off waivers by the Tampa Bay Buccaneers. On February 15, 2012, he was released by the team.

In January 2015, Haynesworth pled guilty for reckless boating charges.

On July 7, 2019, Haynesworth revealed that his kidneys are failing and is seeking a donor for transplant.

On September 28, 2020, Haynesworth was arrested in Cleveland, Tennessee and charged with domestic assault after he was accused of yelling at and threatening his ex-girlfriend and her boyfriend.