This review provides an overview of immunometabolism, focusing on six major metabolic pathways—glycolysis, the tricarboxylic acid (TCA) cycle, the pentose phosphate pathway, fatty acid oxidation, fatty acid synthesis, and amino acid metabolism—and their roles in immune cell function. It highlights how changes in these pathways influence immune responses, particularly in T cells, macrophages, and dendritic cells. The review discusses the interplay between metabolic reprogramming and immunity, emphasizing the importance of metabolic pathways in immune cell activation, survival, and function. It also explores how metabolic pathways are regulated by signaling molecules such as mTOR and AMP kinase, and how these pathways contribute to immune cell differentiation and function. The review emphasizes the growing importance of immunometabolism in understanding immune processes and suggests that future research could yield new insights into immune cell function and disease. Key questions in the field are also presented, highlighting areas requiring further investigation.This review provides an overview of immunometabolism, focusing on six major metabolic pathways—glycolysis, the tricarboxylic acid (TCA) cycle, the pentose phosphate pathway, fatty acid oxidation, fatty acid synthesis, and amino acid metabolism—and their roles in immune cell function. It highlights how changes in these pathways influence immune responses, particularly in T cells, macrophages, and dendritic cells. The review discusses the interplay between metabolic reprogramming and immunity, emphasizing the importance of metabolic pathways in immune cell activation, survival, and function. It also explores how metabolic pathways are regulated by signaling molecules such as mTOR and AMP kinase, and how these pathways contribute to immune cell differentiation and function. The review emphasizes the growing importance of immunometabolism in understanding immune processes and suggests that future research could yield new insights into immune cell function and disease. Key questions in the field are also presented, highlighting areas requiring further investigation.