John Michael Kovac (born 1970) is an American physicist and astronomer. His cosmology research, conducted at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts, focuses on observations of the Cosmic Microwave Background (CMB) to reveal signatures of the physics that drove the birth of the universe, the creation of its structure, and its present-day expansion. Currently, Kovac is Professor of Astronomy and Physics at Harvard University.