Melbourne United (2016–17) After going undrafted in the
2016 NBA draft, Williams joined the
Milwaukee Bucks for the
2016 NBA Summer League in Las Vegas. In five games for the Bucks, he averaged 2.0 points and 2.4 rebounds in 7.6 minutes per game. Williams struggled to make an impact for United off the bench over the first month of the season, which led to speculation of him being released by the club. That was not to be, and on November 6, he had a season-best game with 13 points and seven rebounds in an 82–73 loss to the
Illawarra Hawks. His next best game came on December 11, as he had a 6-point, 10-rebound effort in an 88–81 win over the
Sydney Kings. In the following game however on December 17, Williams went down with a knee injury early in United's 100–90 loss to the
Brisbane Bullets, and was subsequently ruled out for four to six weeks with a Grade 2 medial ligament strain. On January 31, 2017, after fully recovering, Williams was granted a release from his contract to source opportunities to play in the US.
Greensboro Swarm (2017) On February 14, 2017, he was acquired by the
Greensboro Swarm of the
NBA Development League.
Maine Red Claws (2017–18) In June 2017, Williams joined the
Charlotte Hornets for the
2017 NBA Summer League. On September 26, 2017, he signed with the
Boston Celtics for training camp. He was waived by the Celtics on October 5, 2017.
Vaqueros de Bayamón (2018) On April 25, 2018,
Vaqueros de Bayamón of the
Baloncesto Superior Nacional was reported to have signed Williams.
Büyükçekmece (2018–2019) On July 13, 2018, he has signed with
Büyükçekmece of the
Basketball Super League (BSL).
KK Budućnost (2019) On February 14, 2019, Williams signed with
Budućnost of the
Montenegrin League.
Tofaş (2019–2020) On July 2, 2019, he has signed with
Tofaş of the Turkish
Basketball Super League. Williams averaged 15.4 points, 7.5 rebounds and 1.9 assists per game.
Bahçeşehir Koleji (2021) On July 7, 2021, Williams signed with
Bahçeşehir Koleji of the
Basketbol Süper Ligi, (BSL). He played three games and averaged 2.3 points per game. On January 27, 2022, Unicaja Malaga has announced that Devin Williams has failed his medicals and therefore the agreement between the parts has been voided. On February 21, 2022, Williams signed with
Vaqueros de Bayamón.
Taiwan Beer Leopards / Taoyuan Taiwan Beer Leopards (2023–2025) On October 7, 2023, Williams has signed with
TaiwanBeer Leopards of the
T1 League. He was the league's rebounds leader for the
2023–24 season. On August 9, 2024, Williams re-signed with the
Taoyuan Taiwan Beer Leopards of the
Taiwan Professional Basketball League (TPBL). He was the league's rebounds leader for the
2024–25 season. On May 29, 2025, Williams signed with the
Changwon LG Sakers of the
Basketball Champions League Asia (BCL Asia). He was later replaced by Kevin Allen due to a calf injury. ==Personal life==