President Barack Obama's wife will cameo as herself in an instalment of the Nickelodeon show which revolves around the newly-launched Joined Forces initiative.
The national initiative - which is led by Mrs Obama - aims to bring attention to military families and provide support for partners and children of those serving, and military veterans.
Nickelodeon president Cyma Zarghami told The AP that the storyline will see Mrs Obama talking with Carly (Miranda Cosgrove) and her friends after they break the rules to set up a birthday video chat between Carly and her military father serving overseas.
He said the episode was written specifically for the First Lady by creator and executive producer Dan Schneider and is likely to air in January.
The news of Mrs Obama's appearance comes a day after reports that Big Bang Theory star Jim Parsons has signed on for a guest spot on the current fourth season. Other stars to recently cameo on iCarly include Jane Lynch and Jack Black.
This week's episode will see the iCarly cast uniting with the Victorious cast for an original episode called iParty with Victorious, which revolves around Carly and Tori (Victoria Justice) unknowingly dating the same boy and then planning revenge together when they find out.
iCarly was recently renewed for a fifth season.