The constant physiological flux of mitochondrial fission and fusion is inextricably tied to the maintenance of cellular bioenergetics and the fluidity of mitochondrial networks. Yet, the intricacies of this dynamic duo remain unclear in diseases that encompass mitochondrial dysregulation. Particularly, the role of the GTPase fission protein dynamin-related protein 1 (Drp1) is of profound interest. Studies have identified that Drp1 participates in complex signaling pathways, suggesting that the function of mitochondria in pathophysiology may extend far beyond energetics alone. Research indicates that, in stressed conditions, Drp1 translocation to the mitochondria leads to elevated fragmentation and mitophagy; however, despite this, there is limited knowledge about the mechanistic regulation of Drp1 in disease conditions. This review highlights literature about fission, fusion, and, more importantly, discusses Drp1 in cardiac, neural, carcinogenic, renal, and pulmonary diseases. The therapeutic desirability for further research into its contribution to diseases that involve mitochondrial dysregulation is also discussed.