The 38-year-old actor said Wednesday in an interview with Sky News that he's grateful to Bynes, 32, for supporting his casting in the 2006 movie She's the Man.
"She definitely helped. Man, I thank her every day," Tatum said while attending the opening night of Magic Mike Live in London.
"She helped me. She got me in that movie. I'm so happy that she's killing it now and back on her feet. I love her," he added.
Bynes had said in an interview with Paper published this week that she pushed for Tatum's casting in She's the Man while the actor was a relative unknown.
"I totally fought for Channing [to get cast in] that movie because he wasn't famous yet," the actress told the magazine.
"He'd just done a Mountain Dew commercial and I was like, 'This guy's a star -- every girl will love him!'' she recalled. "But [the producers] were like, 'He's so much older than all of you!' And I was like, 'It doesn't matter! Trust me!'"
Tatum starred in such films as Step Up, 21 Jump Street and Magic Mike following his appearance in She's the Man. He is slated for the Marvel movie Gambit, which is scheduled for release in 2020.