The PINK1/Parkin pathway is responsible for targeting damaged mitochondria for degradation via mitophagy. Because genetic evidence links impaired mitophagy to Parkinson’s disease, pharmacologic enhancement of mitophagy represents a promising disease-modifying strategy. Here, we characterize two pharmacological mitophagy activators: a new Parkin activator, FB231, described here and the reported PINK1 activator MTK458. We demonstrate that both compounds activate their targets and lower the threshold for PINK1/Parkin-mediated mitophagy induced by mitochondrial stressors. Using global proteomics, however, we also find that FB231 and MTK458 exert mild mitochondrial stress that leads to cleavage of OPA1 and activation of the integrated stress response, in a PINK1/Parkin-independent manner. Both compounds cause mitochondrial stress and thereby sensitizes cells to mitophagy induction by classical mitochondria toxins. We provide a model that rationalizes this hitherto unknown mechanism for mitophagy activators, whereby normally “silent” mitochondrial toxins can act as potent PINK1/Parkin potentiators in the context of mitochondrial stress.