Golden State Warriors (2017–2018) Prior to the
2017 NBA draft, Boucher was unable to work out with teams due to his injury. He ultimately went undrafted, but was signed by the
Golden State Warriors to a
two-way contract, the same team which purchased a draft pick from the
Chicago Bulls to choose his Oregon teammate
Jordan Bell. Boucher became one of the first players to sign up on the NBA's newest two-way contract policy, which went into effect that season, although his deal was not official until July 14, 2017. On November 2, 2017, Boucher was called up to the
NBA G League by the
Santa Cruz Warriors and made his debut versus the
Reno Bighorns. On March 14, 2018, Boucher made his NBA debut, being called up by the
Golden State Warriors to fill in for the injury-riddled lineup. In his first and only minute of action with Golden State, he recorded 1 rebound and 1 three-point attempt in a 117-106 victory over the
Los Angeles Lakers. Although he was unavailable to play in the
playoffs due to his two-way contract, Boucher was a part of the Warriors championship team after they swept the
Cleveland Cavaliers in four games in the
2018 NBA Finals. On June 22, 2018, the
Golden State Warriors waived Boucher.
Toronto Raptors (2018–2025) On July 20, 2018, Boucher signed with the
Toronto Raptors as a free agent for two years worth just over $2 million. On October 26, the Raptors converted Boucher's contract to an NBA two-way contract. Boucher played 28 games with the Raptors' NBA G League affiliate, the
Raptors 905 where he averaged 27.2 points, 11.4 rebounds and 4.1 blocks, while also shooting 51.0% from the field. Boucher was named the
G League 2018–19 Most Valuable Player and the
league's Defensive Player of the Year, becoming the first player to win both awards concurrently, and the first international player to win the league MVP award. Additionally, Boucher was also named to the
All-NBA G League First Team. On February 10, 2019, the Raptors signed Boucher to a standard NBA contract. The Raptors made it to the
2019 NBA Finals where they defeated Boucher's former team, the
Golden State Warriors. In doing so, Boucher became the first (and so far only) Canadian player to win an NBA title with the NBA's lone Canadian-based franchise. On November 10, 2019, Boucher tied his career high in points by scoring 15 points in a Raptors win over
LeBron James and the
Lakers. On December 22, 2019, Boucher scored 21 points, and set a new career high in the Raptors 110–107 win over the
Dallas Mavericks. Three days later, on December 25, 2019, Boucher set a new career high again with 24 points in a 118–102 loss to the
Boston Celtics. On March 3, 2020, he set a career high in rebounds with 15 in a win against the
Phoenix Suns. On August 10, 2020 in the
Orlando Bubble, Boucher scored a career-high 25 points against the
Milwaukee Bucks. On November 25, 2020, Boucher re-signed with the Raptors for two years worth $13.5 million. On December 26, Boucher had 22 points, 10 rebounds and a career-high seven blocks against the
San Antonio Spurs. On January 14, 2021, Boucher tied a career-high 25 points against the
Charlotte Hornets. On February 6, 2021, Boucher hit another scoring high with 29 points, 10 rebounds and 2 blocks in a loss to the Atlanta Hawks. On March 4, 2021, Boucher had a then-season-high 30 points and five rebounds in a 132–125 loss to the Boston Celtics. Then, on April 8, 2021, he hit another scoring high with 38 points, a career-high 19 rebounds and one assist in a 122–113 loss against the Bulls. On April 18, 2021, Boucher scored 31 points with 12 rebounds, two assists, one steal and one block and hit a career-high six threes in a 112–106 win against the
Oklahoma City Thunder. On June 30, 2022, Boucher re-signed with the Raptors on a three-year, $35.25 million contract. He made 76 appearances for the team during the
2022–23 NBA season, averaging 9.4 points, 5.5 rebounds, and 0.4 assists. With the trade of
Pascal Siakam on January 17, 2024, Boucher became the final remaining player from the 2019 championship team on the Raptors roster. In the
2023–24 season, he appeared in 50 games for Toronto, recording averages of 6.4 points, 4.5 rebounds, and 0.7 assists. Boucher made another 50 appearances for the Raptors in the
2024–25 season, averaging 10.0 points, 4.5 rebounds, and 0.7 assists.
Boston Celtics (2025–2026) On August 10, 2025, Boucher signed a one-year, $3.3 million contract with the
Boston Celtics. He made nine appearances for Boston, posting averages of 2.3 points, 2.0 rebounds, and 0.3 assists. On February 5, 2026, Boucher was traded to the
Utah Jazz in exchange for
John Tonje, but was waived by the team. ==Career statistics==