Caveolae are cell membrane invaginations that were first described in the early 1950s. Since then, researchers have undertaken numerous studies to define their role in normal physiology and disease. The caveolin proteins, particularly caveolin-1, are the major structural and functional components of caveolae, which are involved in a plethora of cellular functions. This review briefly describes the role of caveolae and caveolin proteins in these cellular processes and in different types of human cancers. In addition, it also discusses the use of caveolin-1 as a potential diagnostic and prognostic marker and therapeutic target.