Canonical signal transduction via heterotrimeric G proteins is spatially and temporally restricted, i.e., triggered exclusively at the plasma membrane (PM), only by agonist activation of G-protein-coupled receptors (GPCRs) via a process that completes within a few hundred milliseconds. Recently, a rapidly emerging paradigm has revealed a non-canonical pathway for activation of trimeric G proteins by the non-receptor guanidine-nucleotide exchange factor (GEF), GIV/Girdin. This pathway has distinctive temporal and spatial features and an unusual profile of receptor engagement: Diverse classes of receptors, not just GPCRs can engage with GIV-GEF to trigger such activation. Such activation is spatially and temporally unrestricted, i.e., can occur both at the PM and on internal membranes discontinuous with the PM, and can continue for prolonged periods of time. Here we review the molecular mechanisms that govern non-canonical G protein activation by GIV-GEF and the relevance of this new paradigm in health and disease.