He played 14 seasons in the National Basketball Association (NBA) for the Utah Jazz, Boston Celtics, Charlotte Hornets, and Oklahoma City Thunder.

In the title game, Hayward made the game-winning basket at the buzzer to defeat Marion High School 40–39.

[1] He accepted a scholarship offer from Butler University, coached by Brad Stevens, despite late interest from Purdue and Michigan.

In the championship game of the 2009 Horizon League men's basketball tournament, Butler lost to Cleveland State.

[21] Butler received an at-large bid to the 2009 NCAA Division I men's basketball tournament, and lost in the First Round against the LSU Tigers.

[23][24] Butler lost to Duke in the championship game of the 2010 NCAA Division I men's basketball tournament.

In the final seconds, Hayward attempted a game-winning, buzzer-beating, half-court shot, which hit the backboard and rim, and bounced away.

[27] After the 2010 NCAA basketball tournament, Hayward confirmed that he would submit his name for consideration in the 2010 NBA draft, but did not immediately hire an agent.

[30] Sloan's resignation following an argument during a February game coincided with star point guard Deron Williams being traded, which surprised Hayward.

On April 5, 2011, Hayward had a noticeable performance in an 86–85 victory over the Los Angeles Lakers, finishing with 22 points, 6 rebounds, and 5 assists.

[32] Hayward ended the season with a 34-point game, a career high at the time, in a 107–103 win over the Denver Nuggets on April 13.

[33] As a sophomore in 2011–12, Hayward established himself in the starting lineup, and was selected to play in the 2012 NBA Rising Stars Challenge game.

[34] Hayward made his NBA playoffs debut against the San Antonio Spurs as the Jazz lost 4–0 in the first round.

[38] After the departure of Paul Millsap and Al Jefferson during the 2013 offseason, Hayward emerged as the Jazz's new offensive threat, averaging career highs per game in points, rebounds, assists and steals.

[49] On April 21, 2017, in Game 3 of the Jazz's first-round playoff series against the Los Angeles Clippers, Hayward scored a career-high 40 points in a 111–106 loss.

[55] On October 17, 2017, Hayward suffered a fractured tibia and dislocated ankle in his left leg less than six minutes into the Celtics' regular-season opener against the Cleveland Cavaliers.

He landed awkwardly on the hardwood after an attempted alley-oop off a pass from Kyrie Irving, causing his leg to collapse underneath his weight.

[60] He thus also missed the deep playoff run to the Eastern Conference Finals, where his Boston Celtics lost in seven games to the same Cleveland Cavaliers team he had suffered the gruesome season-ending injury against.

[69] On August 17, 2020, Hayward was injured with a Grade 3 right ankle sprain after improperly landing on teammate Daniel Theis' foot while jumping for a rebound during the 1st round of the playoffs against the Philadelphia 76ers.

[74] On December 23, 2020, Hayward made his Hornets debut, putting up 28 points, seven assists, and four rebounds in a 121–114 loss to the Cleveland Cavaliers.

[76] On December 5, 2021, Hayward scored a season-high 41 points, alongside five rebounds and three assists, in a 131–115 win over the San Antonio Spurs.

[81] He made his return from injury on November 18, recording 13 points, six rebounds and seven assists in a 132–122 overtime loss to the Cleveland Cavaliers.

[83] Hayward made his return to the lineup on December 16, recording nine points, three rebounds, five assists and two steals in a 125–106 loss to the Atlanta Hawks.

[85] On February 24, 2023, Hayward recorded season-highs of 27 points and 13 rebounds, alongside five assists and two steals, in a 121–113 win over the Minnesota Timberwolves.

[87] On February 22, Hayward made his Thunder debut, pulling in four rebounds in a 129–107 win over the Los Angeles Clippers.

[27] In 2014, he was selected as a finalist for the United States FIBA Basketball World Cup team,[92] but he did not make the final 12-man roster.

[103] He was formally received by Archbishop Timothy Broglio at the church of San Sebastiano fuori le mura in Rome.

[113] In October 2018, League of Legends developer Riot Games released an animated commercial in support of Hayward's recovery from an ankle injury while playing for the Boston Celtics.

[115][116][117] On August 9, 2019, he signed an honorary lifetime contract for Hupu, a Chinese League of Legend Teams as its midlaner.