Shams Charania of Yahoo Sports reported details of Noel's contract, with David Aldridge of NBA.com adding that it is for the veteran minimum and that both Russell Westbrook and Paul George were in contact with the big man.
Noel's tenure with the Mavericks never materialized in a way that either side would have liked. He was acquired from the Philadelphia 76ers at the trade deadline in February 2016, averaging 8.5 points and 6.8 rebounds in 22 games after the deal.
Last offseason, he was a restricted free agent hoping to receive a long-term extension. Steve Kyler of Basketball Insiders reported the 24-year-old turned down a deal from Dallas that averaged $17.5 million per season.
After continuing to wait out the market that didn't develop, Noel eventually accepted the $4.1 million qualifying offer from the Mavs for the 2017-18 season in August.
He played sporadically at the start of this season, averaging a career-low 15.7 minutes per game, and missed 42 games after suffering a torn thumb ligament in a November game against the Memphis Grizzlies.
Jonathan Tjarks of The Ringer noted in November Noel's lack of playing time was, in part, due to the Mavs' roster construction:
"There's no room for another traditional center in the Mavs' starting lineup. Opening with Noel moves their other key players out of their best positions. Dirk Nowitzki is 39 years old and in his 20th season in the NBA, and he no longer has the speed to play power forward. Harrison Barnes has been much better at power forward than small forward in two seasons in Dallas, where he can use his strength to match up with bigger players in the post on defense and then take them off the dribble on offense."
Noel also missed the final five games of the regular season when he was suspended for violating the NBA's anti-drug program. He ended the year averaging just 4.4 points and 5.6 rebounds in 30 games played.
Because Noel's value is so low after a disastrous 2017-18 campaign, he's worth a flyer for the Thunder at this point. His ability to play in the paint, get high-percentage shots and grab rebounds has value.
The NBA isn't as driven by size, especially in the paint, as it used to be. Noel has struggled to find a role that works for him and a team, but this latest move gives him an opportunity to carve out a niche that helps him extend a once-promising career that has fallen off the rails.
The Thunder have already made their biggest moves of the offseason by keeping Paul George and Jerami Grant, putting them in a position of paying $286 million next season between player salaries and luxury-tax penalties.
It's a testament to Oklahoma City's front office and ownership that they are willing to dig deep into their pockets to keep pace in the Western Conference.
Noel is a small piece of the Thunder's larger puzzle, but he does give them a backup who can spell Steven Adams as they try to get past the first round of the playoffs for the first time since Kevin Durant left two years ago.