Mitch McGary was born on June 6, 1992, and grew up in the Chesterton, Indiana, area. He played in YMCA and Amateur Athletic Union (AAU) basketball leagues as a youth, and his father, Tim, who had never played organized sports, coached him until fourth grade. McGary’s mother is named Valerie. When McGary was younger, his father thought his athletic future was in baseball. McGary played on the 2007–08 Chesterton High School junior varsity team as a freshman, while eventual three-time Michigan Wolverines captain Zack Novak was a senior on the varsity team. That year he also was a 6-foot-6-inch (1.98 m), 190-pound (86 kg) freshman tight end on the high school football team, but his father made him quit football as he continued to grow. His local Indiana SPY Players AAU basketball team included future Michigan teammates Max Bielfeldt and Glenn Robinson III, son of Glenn Robinson. McGary joined the varsity basketball team the following season and played two years. McGary is afflicted with attention deficit hyperactivity disorder. He eventually transferred to Brewster Academy, a prep school in Wolfeboro, New Hampshire, to repeat his junior year because his parents thought the discipline would be good for him. Before transferring to Brewster, McGary was the tallest kid in his school and in the basketball conference that he played in. McGary shoots left-handed.

In the third game of the season and the third of his career, McGary posted a game-high 9 rebounds in 17 minutes of play off the bench against Cleveland State on November 13. McGary also went 3-for-3 on his field goals. McGary reached double figures in scoring for the first time December 4 against Western Michigan (Michigan’s eighth game of the season) when he scored 10 points on 5-for-5 shooting in 14 minutes of play off the bench. He had his first 10-rebound game on December 11 against the Binghamton Bearcats. On December 20, he posted his first double-double with a then career-high 11 rebounds and 10 points as well as a then career-high 3 steals in just 18 minute of play against Eastern Michigan. On December 24, he was recognized as Big Ten Freshman of the Week. On January 6, McGary tied then career high with 11 rebounds, tied a then career high 2 assists and set a career high with 3 blocked shots against Iowa. On January 28, Michigan was ranked number one in the AP Poll with 51 of the 65 first place votes. It marked the first time Michigan ranked atop the AP Poll since the Fab Five 1992–93 team did so on December 5, 1992.

His reported best friend, Robinson had committed to Michigan on September 14, 2010. In a press conference broadcast on ESPNU on November 3, 2011, McGary announced his verbal commitment to Michigan over his other two finalist Florida and Duke. Within hours of the commitment, ESPN ranked Michigan’s recruiting class the fifth best in the nation. After several other schools announced their commitments, Michigan, which had been outside the top 25 at the end of October, ranked the number 7 class in the nation, according to ESPN. He waited until November 9 to sign his National Letter of Intent so that his parents, who were still living in Indiana, could be present. Both of his parents had liked head coach Mike Krzyzewski and had hoped that he would choose Duke. At the time of their November 2011 National Letter of Intent signings, Nik Stauskas, Robinson and McGary gave Michigan a consensus top 10 entering class for its 2012 class.

McGary was invited to participate in the four-team All-American Championship along with future teammate Robinson in New Orleans on April 1, 2012. Six days later, McGary represented USA Basketball at the 15th annual Nike Hoops Summit as part of the 2012 USA Junior National Select Team. Following the season, he was named as one of 40 Parade All-Americans.

On April 30, ESPN’s Eamonn Brennan named him a first team 2013-14 pre-offseason All-American selection. In June 2013, Sporting News’ Mike DeCourcy named McGary the best center for the upcoming season. McGary declined an invitation to try out for the USA Basketball team that competed at the 2013 Summer Universiade, opting instead to attend the Nike Skills Academy for big men featuring Amar’e Stoudemire and Anthony Davis and the LeBron James Skills Academy.

McGary was drafted 21st overall by the Oklahoma City Thunder. With teammates Stauskas and Robinson also being drafted, it marked the first time Michigan had at least three draft picks since the 1990 NBA draft. With Burke and Hardaway having been drafted the year before, every player that started in the 2013 NCAA Men’s Division I Basketball Championship Game was drafted either in the 2013 or 2014 NBA draft.

On July 5, 2014, McGary signed with the Thunder and joined them for the 2014 NBA Summer League. On the first possession of his first NBA Summer League game, McGary issued a halfcourt pass for a lob slam dunk by Jeremy Lamb, highlighting the passing that he is known for. On October 8 during training camp, McGary fractured the second metatarsal of his left foot, causing him to be sidelined for an estimated six weeks. This occurred three weeks before the team’s October 29 season opener and meant McGary was expected to miss the first 14 games of the season. After missing the first 14 games, he began to be a limited participant in practices. McGary debuted with the Thunder on December 14 with 4 rebounds and 3 points in 7:15 of play against the Phoenix Suns. Subsequently, McGary was sidelined for 2–3 weeks with periostitis (inflammation) in his left tibia. He returned from injury on February 2 as he appeared in just his second NBA game in a 104-97 win over the Orlando Magic. On February 8, in his third NBA game, McGary posted a double double with 19 points and 10 rebounds against the Los Angeles Clippers, while energizing the crowd and team. Then on February 9, he posted a 17-point, 10-rebound double double against the Denver Nuggets. He was one of the finalists for NBA Western Conference Rookie of the Month. On March 13, McGary made his first start against the Minnesota Timberwolves in place of an injured Serge Ibaka, scoring 12 points in 22 minutes. At power forward, his defensive assignment was supposed to have been Kevin Garnett, but Garnett sat out a third consecutive game and was replaced by fellow rookie (and former Michigan State rival) Adreian Payne who had replaced Garnett in the two previous games as well. McGary had made his first college basketball start against Payne’s 2012–13 Michigan State team. On March 16, McGary established a new career high by nabbing 11 rebounds in his first 6 minutes of play before going on to post a double double with 13 rebounds and 12 points in 17 minutes against Dallas Mavericks. In the April 15 season finale against the Minnesota Timberwolves, McGary posted a season-high 4 blocked shots in just 14:54 of play. During his rookie and sophomore seasons, he had multiple assignments with Oklahoma City Blue, the Thunder’s D-League affiliate.

On October 16, 2015, McGary suffered a loose ball collision with Matt Barnes of the Memphis Grizzlies that resulted in concussion-like symptoms. On October 21, the Thunder exercised their third-year team option on McGary’s rookie scale contract, extending the contract through the 2016–17 season. On October 26, he was cleared for the October 28 season opener. However, McGary did not appear in the game. He went on to play limited minutes in 20 games before leaving the team prior to the end of the season for “personal reasons”.

On July 8, 2016, McGary was suspended for five games by the NBA for a failed drug test. Two months later, he was suspended an additional 10 games for non-compliance with the league’s drug policy, bringing the number of regular season games he is suspended without pay for to 15. On October 24, 2016, following preseason, McGary was waived by the Thunder. If McGary signs with another NBA team, he can begin serving his 15-game suspension at that time.

By 2017, he returned to bowling, a sport of his youth and that his mother competed at for 29 years, but still felt more basketball might be in his future.