According to the Associated Press, Obama will promote Joining Forces, the initiative focused on increasing awareness and support for military families.
In the episode, Carly (Miranda Cosgrove) and her friends break some rules to set up a web chat so Carly can speak with her father -- who is serving overseas -- on his birthday.
After the rule-breaking, "the first lady discovers it and comes to have a chat with them in the most positive way possible," Nickelodeon president Cyma Zarghami told AP.
The episode was written specifically for Obama and the Joining Forces program and will likely air in January. Zarghami said the Obama children are fans of the 'iCarly.'
In 2009 Obama appeared on an episode of 'Sesame Street,' but most of her TV appearances have been on talk shows or unscripted programs.
Tell us: Do you think Michelle Obama should make more scripted TV appearances?