Autophagy is a conserved cellular degradation pathway for the breakdown of cytosolic macromolecules and organelles. Constitutive autophagy has a housekeeping role and is essential for survival, development and metabolic regulation. Autophagy is also responsive to stress and can degrade damaged proteins and organelles, oxidized lipids and intracellular pathogens. Defects in the autophagic degradation system are linked to disease pathogenesis and ageing. Different signalling pathways converge on autophagy to regulate lifespan in diverse organisms. We discuss recent findings that provide insight into the cross-talk between this critical regulator of metabolic homeostasis and molecular mechanisms that promote longevity.