Summitt was born Patricia Sue Head on June 14, 1952 in Clarksville, Tennessee, the daughter of Richard and Hazel Albright Head. In her early years, she was known as Trish. She had four siblings: older brothers Tommy, Charles, and Kenneth, and a younger sister, Linda.

Summitt was named to the U.S. women’s basketball team invited to compete at the 1975 Pan American Games. The team was coached by future Hall of Fame coach Cathy Rush. Players included Lusia Harris, Nancy Lieberman, Ann Meyers, and Juliene Simpson. After winning the gold medal in 1963, the USA team lost to Brazil in both 1967 and 1971 and had recently competed in the 1975 World Championship, finishing in eighth place. The opening game was against host-country Mexico which had finished ahead of the USA team at the World Championships. This time, the USA was victorious, beating Mexico 99–65. The USA would go on to win its next five games, all but one by a double-digit margin. That set up the gold medal game against Brazil which the USA team won convincingly, 74–55.

When Summitt was in high school, her family moved to nearby Henrietta so she could play basketball in Cheatham County, because Clarksville did not have a girls team. From there, Summitt went to University of Tennessee at Martin, where she was a member of Chi Omega Sorority and won All-American honors playing for UT–Martin’s first women’s basketball coach, Nadine Gearin. In 1970, with the passage of Title IX still two years away, there were no athletic scholarships for women. Each of Summitt’s brothers had received athletic scholarships, but her parents paid her way to college. She later co-captained the United States women’s national basketball team as a player at the inaugural women’s tournament in the 1976 Summer Olympics, winning the silver medal. Eight years later in 1984, she coached the U.S. women’s team to an Olympic gold medal, becoming the first U.S. Olympian to win a basketball medal and coach a medal-winning team.

During Summitt’s first year as head coach, four of her players were only a year younger than she was and all were from Tennessee high schools, which until 1980 employed a six-person game where offensive and defensive players never crossed mid-court. She coached her first game for Tennessee on Dec. 7, 1974 against Mercer University in Macon, Georgia; the Lady Vols lost 84–83. Her first win came almost a month later when the Lady Vols defeated Middle Tennessee State, 69–32 on Jan. 10, 1975. The Lady Vols won the Tennessee College Women’s Sports Federation (TCWSF) Eastern District Championship for the third straight year. However, the team finished 4th overall in the TCWSF (they had been second the previous two years), and were not invited to the Association for Intercollegiate Athletics for Women (AIAW) tournament.

In her second season, Summitt coached the Lady Vols to a 16–11 record while earning her 1976 master’s degree in physical education and training as the co-captain of the 1976 U.S. Women’s Olympic basketball team that won a silver medal in Montreal. Starting with the 1976–77 season, Summitt directed two 20-win teams, winning back-to-back AIAW Region II championships. The Lady Vols defeated 3-time AIAW champion Delta State by 20 points in 1978, and earned Tennessee its first number one ranking. 1978 saw the Lady Vols participate in their first AIAW Final Four, where they finished third. Summitt also recorded her 100th win during this season, a 79–66 victory over NC State. Tennessee closed the 1970s by winning the first-ever SEC tournament, and returning to the AIAW Final Four, where they finished runner-up to Old Dominion, 68–53.

Summitt married Ross Barnes Summitt II in 1980. The couple had one son, Ross Tyler Summitt, born in 1990. Summitt filed for divorce from her husband in 2007.

Summitt was chosen as the head coach of the team representing the USA in 1984 at the William Jones Cup competition in Taipei, Taiwan. The team chosen to represent the USA was the team expected to be selected as the national team for the 1984 Olympic Games. This resulted in a very strong team which was able to dominate the competition. In the opening game against Australia, the USA won 82–20. While other games were closer, Italy’s 23-point loss to the USA was the closest of the eight games. The USA won all eight games and the gold medal, and three of the team’s players were named to the All-Tournament Team.

The 1996–97 Lady Vols posted one of the worst records ever for a Summitt-coached team. In addition to losses to powerhouses such as Louisiana Tech (twice), Stanford, Old Dominion, and Connecticut, Tennessee fell to teams such as Florida, against whom they had been previously undefeated. Summitt earned her 600th win with a 15-point victory over Marquette on November 23, 1996. Summitt and the 1996–97 championship team were the subject of an HBO documentary titled A Cinderella Season: The Lady Vols Fight Back. The Lady Vols posted a 23–10 record heading into the NCAA tournament. However, Tennessee righted itself during the tournament, shocking previously undefeated Connecticut in the regional final before defeating Notre Dame and Old Dominion in the Final Four to win the team’s second straight national championship.

At the 2000 ESPY awards, the Lady Vols basketball team was named co-team of the decade, along with the Florida State Seminoles football team. Additionally, Pat Summitt was named the Naismith Coach of the Century and Chamique Holdsclaw earned recognition as Naismith Women’s Collegiate Player of the Century.

Summitt won 16 Southeastern Conference regular season titles with the Lady Vols, as well as 16 tournament titles. Summitt’s Lady Vols made an appearance in every NCAA Tournament from 1982 until her retirement, advanced to the Sweet 16 every year except 2009, and appeared 18 times in the Final Four. When Summitt made her 13th trip to the Final Four as a coach in 2002, she surpassed John Wooden as the NCAA coach with the most trips to the Final Four. Summitt was a seven-time SEC Coach of the year and a seven-time NCAA Coach of the year and won three consecutive national titles from 1996 to 1998. Summitt was known for scheduling tough opponents for her team to play in the regular season, in order to prepare them for the postseason. In her years of coaching, her teams played Top 10-ranked teams over 250 times.

Summitt was widely recognized as one of the toughest coaches in college basketball history, men’s or women’s. She was best known for giving her players an icy stare in response to poor play, known simply as “The Summitt Stare.” However, she claimed that she mellowed considerably later in her career. In 2007, Summitt told U.S. News and World Report that she didn’t yell at her players nearly as much as she had earlier in her career. On at least two occasions, Tennessee asked Summitt to consider coaching the men’s team: once before 1997 and again in 2001.

The 2007–08 season started off with the top-ranked Lady Vols going 3–0, including wins over 9th-ranked Oklahoma and 22nd-ranked Texas. The win over Texas was Summitt’s 950th. After two more wins, top-ranked Tennessee knocked off fourth-ranked North Carolina, 83–79, in a rematch of the previous year’s Final Four match-up. Tennessee won their next four games, then headed to California for a match-up with 5th-ranked Stanford. Down by 4 with less than 30 seconds remaining, the Lady Vols managed to tie the game up and send it to overtime, but lost, 73–69. The Lady Vols responded by winning their next seven games, giving them a 17–1 record going into a match-up with Duke. Candace Parker’s 17 points and 12 rebounds, including a bucket with 22 seconds remaining, helped the Lady Vols defeat the Blue Devils for the first time in four years, 67–64. Tennessee would win the rest of their regular season games and defeat LSU for the SEC Tournament Championship. The Lady Vols won four straight games in the NCAA Tournament heading toward their third matchup of the year against the LSU Lady Tigers in the Final Four. Alexis Hornbuckle tipped in a Nicky Anosike missed layup with 0.7 seconds left to win the game, 47–46. On April 8, 2008, Tennessee won its second consecutive national championship (and eighth overall) by beating Stanford 64–48.

Summitt’s first milestone of the 2008–09 season was a 73–43 win over the Georgia Lady Bulldogs on February 5, 2009 at Thompson–Boling Arena in Knoxville. The win was number 1000 for Coach Summitt. The Thompson–Boling Arena’s court was named “The Summitt” in her honor. The 2008–09 season ended with a dubious first, as the Lady Vols lost 71–55 in the first round of the NCAA tournament to Ball State in Bowling Green, Kentucky, marking the first time Tennessee would not appear in the Sweet 16 since the NCAA first sanctioned championships in women’s basketball for the 1981–82 season.

Summitt was diagnosed with early-onset Alzheimer’s disease in 2011. Despite the diagnosis, she completed the 2011–2012 season in a reduced role, with Holly Warlick (an assistant under Summitt since 1985) assuming most of the coaching responsibilities. In an interview with GoVolsXtra.com, Summitt stated, “There’s not going to be any pity party and I’ll make sure of that.” In December 2011, Summitt was honored as the Sports Illustrated sportswoman of the year.

In August 2011, Summitt announced that she had been diagnosed three months earlier with early-onset Alzheimer’s disease. She retired from coaching in 2012.

On April 18, 2012, after the Lady Vols lost to the unbeaten eventual champion Baylor Lady Bears in the Elite Eight in Des Moines, Summitt stepped down as head coach, ending her 38-year coaching career at age 59. Warlick was named Summitt’s successor. In a statement accompanying her resignation, Summitt said, “I feel like Holly’s been doing the bulk of it. She deserves to be the head coach…” Summitt was given the title Head Coach Emeritus upon her resignation. According to NCAA regulations, as head coach emeritus, she was able to attend practices and assist Warlick in some duties, but was not allowed to sit on the team bench.

Summitt was presented the USBWA Most Courageous Award at the 2012 Final Four, and future awards were given in her name. She received the Arthur Ashe Courage Award in 2012, saying in her acceptance speech: “It is time to fight.”

Summitt received the Presidential Medal of Freedom from President Barack Obama in 2012.

Tyler Summitt, who played as a walk-on for the Tennessee men’s basketball team, graduated from Tennessee in May 2012, was hired as an assistant coach by the Marquette University women’s team effective with the 2012–13 season. In what ESPN.com columnist Gene Wojciechowski called “a bittersweet irony”, Tyler’s hiring by Marquette was announced on the same day his mother announced her retirement.

Summitt died on June 28, 2016, two weeks after her 64th birthday, at a senior living facility in Knoxville. She left the entirety of her estate to her son, Tyler.

After her death, the Pat Summitt Alzheimer’s Clinic was opened at the University of Tennessee Medical Center, with funds from her Foundation. In 2017, the NCAA established the Pat Summitt Award to recognize individuals who positively influence college athletes.