The Target of Rapamycin (TOR), a protein kinase, is the central node of a highly conserved signaling network that regulates cell growth in response to nutrients, hormones, and stresses. TOR is found in two functionally distinct complexes, TORC1 and TORC2. In this review we address the most recent advances in TOR signaling in invertebrate model organisms, including yeasts, plants, worms, and insects.