Acute kidney injury is the sudden loss of kidney function that occurs within hours or days, resulting in the accumulation of waste materials in the blood and disruption of fluid balance. AKI is prevalent among hospitalized patients, especially the elderly in the intensive care units. Inflammation, oxidative stress, and apoptosis are typical physiological responses following AKI. Peptides, especially bioactive peptides, exhibit various properties, including immunomodulatory and antihypertensive effects, and functions against diabetes, obesity, and cancer. In recent years, much attention has been drawn to the application of peptides and bioactive peptides in pharmaceuticals, particularly for their potential use, alone or in combination, in the treatment of AKI. Given the critical role of inflammation, oxidative stress, and apoptosis pathways in AKI, along with the anti-inflammatory, anti-apoptotic, and antioxidant effects of peptides, this study was designed to review the effects and underlying mechanisms of peptides in AKI.