Steve Carell, Emma Stone, Jason Segel and Jesse Eisenberg are also among the names expected to take to the stage in Los Angeles next month.
Other announced presenters include Monte Carlo stars Selena Gomez, Leighton Meester and Katie Cassidy, Transformers: Dark of the Moon stars Shia LaBeouf, Rosie Huntington-Whiteley and Jason Duhamel, and Reynolds's Green Lantern co-star Blake Lively.
Last year's host Aziz Ansari, Danny McBride, Patrick Dempsey and Nicki Minaj have also been confirmed to appear at the annual ceremony.
It was previously confirmed that Jason Sudeikis will serve as host.
The Twilight Saga: Eclipse and Inception will enter the night as the leading nominees, while other movies that could take home a prize include Harry Potter and the Deathly Hallows: Part 1 and Black Swan.
The MTV Movie Awards 2011 air live from the Gibson Amphitheatre in Universal City, California on Sunday, June 5 at 9/8c on MTV.
> In Full - MTV Movie Awards 2011: Nominees