Atherosclerosis is a chronic inflammatory vascular disease and one of the leading causes of death worldwide. Macrophages play an important role in atherosclerosis in the inflammatory response, cell-cell communications, plaque growth, and plaque rupture in atherosclerotic lesions. Here we review the sources, functions, and complex phenotypes of macrophages in the progression of atherosclerotic, and discuss the recent approaches in modulating macrophage autophagy and phenotypic transformation for atherosclerosis treatment. We then focus on the drug delivery strategies that target macrophages or use macrophage membrane-coated particles to deliver therapeutics to the lesion sites. These biomaterial-based approaches to target, modulate, or engineer macrophages have broad applications for disease therapies and tissue regeneration.