Who sang the theme song icarly Miranda or jennete?

The theme song for "iCarly," titled "Leave It All to Me," was performed by Miranda Cosgrove, who played the lead character, Carly Shay. Jennette McCurdy, who played Sam Puckett, did not sing the theme song, although she contributed to the show in other ways. Miranda's vocals and the catchy tune helped establish the show's identity.