In late June 2015, the Worcester Wolves released Owumi as part of a major roster shake-up that left only one player on the team.
On December 18, 2015, Owumi returned to the BBL, signing with the London Lions for the rest of the 2015–16 season.
He said, "I always felt I would be back and I'm happy it's in the Capital.
Yes, I've been through a lot but I'm old fashioned and I just want to work hard."
Owumi debuted on the same day with 11 points in a loss against the Sheffield Sharks.
He recorded 22 points and a season-best 9 rebounds as the Lions fell to the Surrey Scorchers on February 12.
On March 30, he posted another season-high of 27 points, 19 of which came in the first quarter, in a victory over the Cheshire Phoenix.
At the end of the 24-game season, he was averaging 13.4 points, 3.9 rebounds, 2.3 assists, and 0.8 steals per game.

On August 14, 2016, the Lions announced that Owumi would return for the 2016–17 season.
In his first game of the season on September 24, he scored 18 points and had 9 rebounds helping beat the Surrey Scorchers.
In a BBL Cup win over the Plymouth Raiders on October 9, he made 9 three-pointers in a season-high 32-point effort.
Owumi scored 23 points off 8-of-13 shooting, with 19 in the first half, on October 26 against the Leeds Force to help the Lions achieve a 6–0 start to the season.
In a rematch with the Scorchers on November 2, Owumi notched 27 points, converting on all 11 free throw attempts.
London coasted to a 30-point win.
On New Year's Day 2017, he recorded ten points and had 11 assists to overcome a poor shooting night against Surrey.
Owumi had a triple-double of 15 points, ten rebounds, and ten assists as the Lions beat the Raiders on March 10.
He entered the BBL Play-off with hopes of making a run.
However, the Riders ousted London in the semifinals, despite a 21-point night by Owumi.
He finished the season with per-game averages of 13.8 points, 5.1 rebounds, 3.5 assists, and 1.0 steals.
In late June 2015, the Worcester Wolves released Owumi as part of a major roster shake-up that left only one player on the team. On December 18, 2015, Owumi returned to the BBL, signing with the London Lions for the rest of the 2015–16 season. He said, "I always felt I would be back and I'm happy it's in the Capital. Yes, I've been through a lot but I'm old fashioned and I just want to work hard." Owumi debuted on the same day with 11 points in a loss against the Sheffield Sharks. He recorded 22 points and a season-best 9 rebounds as the Lions fell to the Surrey Scorchers on February 12. On March 30, he posted another season-high of 27 points, 19 of which came in the first quarter, in a victory over the Cheshire Phoenix. At the end of the 24-game season, he was averaging 13.4 points, 3.9 rebounds, 2.3 assists, and 0.8 steals per game.
On August 14, 2016, the Lions announced that Owumi would return for the 2016–17 season. In his first game of the season on September 24, he scored 18 points and had 9 rebounds helping beat the Surrey Scorchers. In a BBL Cup win over the Plymouth Raiders on October 9, he made 9 three-pointers in a season-high 32-point effort. Owumi scored 23 points off 8-of-13 shooting, with 19 in the first half, on October 26 against the Leeds Force to help the Lions achieve a 6–0 start to the season. In a rematch with the Scorchers on November 2, Owumi notched 27 points, converting on all 11 free throw attempts. London coasted to a 30-point win. On New Year's Day 2017, he recorded ten points and had 11 assists to overcome a poor shooting night against Surrey. Owumi had a triple-double of 15 points, ten rebounds, and ten assists as the Lions beat the Raiders on March 10. He entered the BBL Play-off with hopes of making a run. However, the Riders ousted London in the semifinals, despite a 21-point night by Owumi. He finished the season with per-game averages of 13.8 points, 5.1 rebounds, 3.5 assists, and 1.0 steals.
Alex Owumi