The Target of Rapamycin (TOR) is a highly conserved protein kinase that regulates cell growth and metabolism through two distinct complexes, TORC1 and TORC2. Each complex regulates different downstream targets; however, both are activated and regulated on lipid membranes. In this Perspective, we will revise the structural biology of TOR complexes and the molecular mechanisms governing their regulation, highlighting the importance of lipid membranes for their function.