The NBC comedy was recently picked up for a fourth season, but early reports suggested that Harmon may not continue as showrunner following his feud with cast member Chevy Chase.
However, Harmon wrote on Twitter: "Guys, if I 'didn't come back', it wouldn't be because Chevy's a pr*ck. That'd be like punching a wall because water's wet. Now celebrate!"
Community star Alison Brie recently played down rumours of a feud between Harmon and Chase, calling their verbal clash "a little rift in the tides".
"[Getting picked up] means more to me than whatever mini-dramas are happening behind the scenes," said the actress. "They're not at the forefront of everyone's mind all the time."
Chase has suggested that the Community writers don't know "what to do" with him, calling his character Pierce Hawthorne only "moderately funny".
"I don't think anyone has a sense of what to do with me," he argued. "I just don't think the writing of that character reflects what I do comedically, [although] I love the people I work with."
Community continues on Thursdays at 8/7c on NBC. In the UK, the series airs on Tuesdays at 10.30pm on Sony Entertainment Television.