Centre Fédéral (2015–2016) At age 14, Doumbouya moved to the renowned French sports institute
INSEP in
Paris and joined its affiliated club
Centre Fédéral de Basket-ball, a member of the
Nationale Masculine 1 (NM1), the amateur
third-tier division of French basketball. He made his 2015–16 season debut on 26 September 2015, recording 12 points, five rebounds, and three steals against Aurore de Vitré. In turn, Doumbouya became the first player born in the 2000s to play in the top three French leagues. On 8 March 2016, he scored a season-high 23 points in a loss to
Vendée Challans. Doumbouya finished the season averaging 10.6 points, 3.3 rebounds, 1.2 assists, and 1.4 steals per game.
Poitiers Basket 86 (2016–2018) in March 2017 On 26 August 2016, at age 15, Doumbouya signed his first professional contract with
Poitiers Basket 86 of the
LNB Pro B, the second-tier French league. At the time, he revealed his hopes to play in the
National Basketball Association (NBA) within the following three years. While with Poitiers, he attended
private school to work towards his diploma, and tried to model the focus he saw in former NBA player
Michael Jordan with the help of a
sports psychologist. In his first Pro B season game on 14 October 2016, he scored two points in six minutes off the bench against
Étoile Charleville-Mézières. He scored double figures for the first time on 20 January 2017, in an 81–63 loss to
Fos Provence, posting a team-high 16 points on 7-of-11 shooting. In his next game, a defeat to
Lille Métropole, Doumbouya scored a season-high 21 points and nine rebounds, shooting 3-of-3 from the three-point line. He finished the season averaging 6.8 points, 3.3 rebounds, and 0.8 assists in 16.9 minutes per game. On 29 September, he notched a
double-double of 15 points and 12 rebounds in a 76–71 win over
Hermine Nantes at the LNB Pro B Leaders Cup. Doumbouya debuted in the
2017–18 Pro B season against
Denain Voltaire on 13 October 2017, recording seven points and four rebounds in 16 minutes. On 22 December, he scored a season-best 19 points and eight rebounds in a loss to
Saint-Chamond. Doumbouya eclipsed that mark on 2 February 2018, in a career-high 26-point effort against
UJAP Quimper 29. In 28 games, he averaged 8.5 points, 4.1 rebounds, and one assist in 23.2 minutes per game, en route to earning Pro B Best Young Player honors.
Limoges CSP (2018–2019) in September 2018 In May 2018, Doumbouya revealed plans to join a team in the
LNB Pro A, the top basketball league in France. On 25 June 2018, he signed with
Limoges CSP of the Pro A. Head coach Kyle Milling praised the newcomer: "Despite his age, next season, I rely on him being an impact player. He has tremendous physical qualities: running, counterattack and speed." Doumbouya debuted for Limoges on 22 September 2018, recording two points and four rebounds in 11 minutes against
Antibes. On 17 October, he scored 11 points, shooting 4-of-6 from the field, in a 102–93 loss to
Alba Berlin in the
EuroCup. In late December, Doumbouya scored 12 points in three straight games in the EuroCup and Pro A, shooting a combined 14-of-17 from the field. On 26 December, he suffered a right thumb injury that required surgery. Doumbouya returned to action on 9 February, scoring nine points and grabbing five rebounds versus
Strasbourg. On 9 March, he recorded a season-high 14 points, five rebounds, and two blocks in an 85–73 loss to
Monaco. Doumbouya erupted for a career-high 34 points, with five three-pointers and nine rebounds, on 18 May, in a 106–78 regular season finale win over
Levallois Metropolitans. In 29 Pro A games, including two playoff contests, he averaged 7.7 points and 3.2 rebounds per game. In eight EuroCup appearances, Doumbouya averaged 6.9 points and 2.8 rebounds per game. He became the first player born in Guinea to be drafted into the NBA. Doumbouya missed his team's first four games at the
2019 Las Vegas NBA Summer League with hamstring pain and scored nine points in his only appearance, during a 105–85 loss to the
Brooklyn Nets. In his rookie season, he was the
youngest active player in the NBA. He suffered a
concussion during practice on 9 October and was sidelined for multiple games after being placed into the concussion protocol program. On 4 November, before playing an NBA game, Doumbouya was assigned to the Pistons'
NBA G League affiliate, the
Grand Rapids Drive. He made his G League debut four days later, scoring 12 points in a 109–94 win over
Raptors 905. On 23 November 2019, Doumbouya was recalled by the Pistons and made his NBA debut in a 104–90 loss to the
Milwaukee Bucks. In early January 2020, he registered double-doubles in each of his first two starts against the
Los Angeles Clippers and the
Golden State Warriors. On 15 January, Doumbouya scored a season-high 24 points with two rebounds, an assist and a steal in a 116–103 victory over the
Boston Celtics. His production declined after the performance, and he scored at least 10 points in one more NBA game for the rest of the season. On 6 March, Doumbouya was assigned to the G League, recording 30 points and eight rebounds and making a game-winning jump shot in a 102–101 win over the
Maine Red Claws. In the
2019–20 NBA season, he averaged 6.4 points and 3.1 rebounds in 19.8 minutes per game, starting in 19 of his 38 appearances.
Los Angeles Lakers (2021–2022) On 4 September 2021, Doumbouya and
Jahlil Okafor were traded to the
Brooklyn Nets in exchange for
DeAndre Jordan and multiple second-round draft picks. On 6 October, Doumbouya was again traded, alongside a 2024 second-round pick, to the
Houston Rockets in exchange for cash considerations. He was waived the following day. On 12 October, the
Los Angeles Lakers signed Doumbouya to a two-way contract with the
South Bay Lakers of the
NBA G League. On 16 November, Doumbouya was waived by the Lakers, after appearing in two games, to make room for
Chaundee Brown. On 12 January 2022, the Lakers re-signed Doumbouya to a two-way contract. However, before appearing in a game during his second stint with the team, he was waived on 1 March.
Delaware Blue Coats (2022–2023) On November 4, 2022, Doumbouya was named to the opening night roster for the
Delaware Blue Coats, and eventually helped the team win the
NBA G League title.
Chorale Roanne Basket (2024) On 23 February 2024, Doumbouya signed with
Chorale Roanne Basket of the
LNB Pro A.
MoraBanc Andorra (2024–2025) On July 14, 2024, he signed with
MoraBanc Andorra of the Spanish
Liga ACB.
Sagesse Club (2025) On May 29, 2025, he signed with
Sagesse Club of the
Lebanese Basketball League (LBL). ==National team career==