Providing optimal nutrition support in the intensive care unit (ICU) is a challenging and dynamic process. Energy, protein, fluid, electrolyte, and micronutrient requirements all can be altered in patients with acute, chronic, and acute‐on‐chronic kidney disease. Given that renal dysfunction occurs in up to one‐half of ICU patients, it is imperative that nutrition support providers understand how renal dysfunction, its metabolic consequences, and its treatments, including renal replacement therapy (RRT), affect patients' nutrition needs. Data on nutrient requirements in critically ill patients with renal dysfunction are sparse. This article provides an overview of renal dysfunction in the ICU and identifies and addresses the unique nutrition challenges present among these patients, including those receiving RRT, as supported by the available literature and guidelines.