Also to appear in the small screen comedy "Gym Teacher: The Movie" are Nathan Kress, Amy Sedaris and David Alan Grier.
Olympian Bruce Jenner will have a cameo as well in the film, which is set to air in August, Nickelodeon said.
Best known for his roles in the TV dramas "Law & Order: SVU" and "Oz," Meloni will play a former gymnastics gold medal contender-turned gym teacher in his latest project.
"'Gym Teacher: The Movie' truly has something for everyone in the family, with its blend of broad comedy, sports competition and romance," Nickelodeon's Marjorie Cohn said in a statement. "Christopher Meloni is one of the most versatile actors around, and alongside him is Nathan Kress from Nickelodeon's 'iCarly' as the uncoordinated new student, in a funny yet touching story of redemption, for all those who like to root for the underdog."