The second year is a player option.
The agreement was first reported Yahoo! Sports.
Noel, 24, was drafted sixth overall by the New Orleans Pelicans in 2013 and then traded to the Philadelphia 76ers. He appeared in 30 games last season for the Dallas Mavericks, averaging 4.4 points and 5.6 rebounds.
Noel dealt with a thumb injury that caused him to miss a lot of time last season, and was suspended five games in early April for violating the league's anti-drug program.
According to his former agent, Happy Walters, Noel turned down a $70 million extension from the Mavs last summer to instead sign the team's $4.1 qualifying offer to become an unrestricted free agent this summer.
After gaining commitments from small forwards Paul George and Jerami Grant as free agency opened, the Thunder turned to fill out other areas of the roster with a focus on strengthening the frontcourt.