Boston Celtics (2019–2022) Langford was selected with the 14th overall draft pick by the
Boston Celtics in the
2019 NBA draft. On July 11, 2019, Langford signed his rookie scale contract with the Celtics. Langford was assigned to the
Maine Red Claws for the start of the
NBA G League season. He rolled his ankle in a game against the
Fort Wayne Mad Ants on November 15. On September 22, 2020, the Celtics announced that Langford had undergone surgery to repair the
scapholunate ligament of his right wrist and would miss the remainder of the
2019–20 NBA season. After his injury-riddled rookie season, Langford made his sophomore debut on April 4, 2021, against the
Charlotte Hornets. He continued to be a semi-constant rotation player for the rest of the season and showed intriguing signs of future potential in the 18 regular season games he played. As injuries continued to plague the Celtics into the 2021 NBA playoffs, Langford took on a larger role. In four of the five playoff games for Boston, he averaged more than 27 minutes per game. With the absences of
Jaylen Brown,
Kemba Walker, and
Robert Williams, Langford's expanded playoff opportunity showed glimpses of individual progression, notably in Game 5 against the
Brooklyn Nets where he dropped a playoff career-high 17 points to go along with two steals and two blocks. Langford played for the Celtics in the
2021 NBA Summer League. On December 31, 2021, he scored a season-high 16 points, alongside three rebounds and two steals, in a 123–108 win over the
Phoenix Suns.
San Antonio Spurs (2022–2023) On February 10, 2022, Langford was traded, alongside
Josh Richardson, to the
San Antonio Spurs in exchange for
Derrick White. Langford made his Spurs debut on March 7, scoring seven points in a 117–110 win over the
Los Angeles Lakers. On December 29, 2022, Langford scored a career-high 23 points, alongside three rebounds, two assists and two steals, in a 122–115 win over the
New York Knicks.
Salt Lake City Stars (2023-2024) On August 30, 2023, Langford signed with the
Utah Jazz, but was waived on October 17. On October 30, he joined the
Salt Lake City Stars. In the 2023–24 season for SLC, including both regular season and tip-off tournament, Langford played in 30 games (22 starts). In the regular season he averaged 29.5 minutes, scoring 11.9 points and 4.1 rebounds per game.
BCM Gravelines-Dunkerque (2024) On October 29, 2024, Langford signed for six weeks with
BCM Gravelines-Dunkerque of the
LNB Élite. On November 29, Langford and BCM Gravelines-Dunkerque mutually agreed to terminate his contract. ==Career statistics==