Macrophages are cells of the innate immune system that regulate the maintenance of tissue homeostasis, host defense during pathogen infection, and tissue repair in response to tissue injury. Recent studies indicate that macrophage functions are influenced by cellular metabolism, including lipid metabolism. Here, we review how macrophage lipid metabolism can be dynamically altered in different physiological and pathophysiological contexts and the key regulators involved. We also describe how alterations in lipid metabolism are integrated with the signaling pathways that specify macrophage functions, allowing for coordinated control of macrophage biology. Finally, we discuss how dysregulated lipid metabolism contributes to perturbed macrophage functions in settings such as atherosclerosis and pathogen infections.