Clusters of galaxies are massive enough to be considered representative samples of the Universe, and to retain all of the heavy elements synthesized in their constituent stars. Since most of these metals reside in hot plasma, X-ray spectroscopy of clusters provides a unique and fundamental tool for studying chemical evolution. I review the current observational status of X-ray measurements of the chemical composition of the intracluster medium, and its interpretation in the context of the nature and history of star and galaxy formation processes in the Universe. I provide brief historical and cosmological contexts, an overview of results from the mature ASCA observatory database, and new results from the Chandra and XMM-Newton X-ray observatories. I conclude with a summary of important points and promising future directions in this rapidly growing field.

18 pages; to appear in Carnegie Observatories Astrophysics Series, Vol. 4: Origin and Evolution of the Elements, ed. A. McWilliam & M. Rauch (Cambridge: Cambridge Univ. Press)