Charles Tsun-Chu Liu is an American astronomer and astronomy educator. His research interests include merging and colliding galaxies, active galactic nuclei, and the star formation history of the universe. Liu is one of the original team members of the Cosmic Evolution Survey (COSMOS), the largest contiguous deep field ever observed with the Hubble Space Telescope. He is a former director of the William E. Macaulay Honors College and The Verrazano School at the City University of New York’s College of Staten Island. He currently serves as a professor of physics and astronomy at the College of Staten Island, and as President of the Astronomical Society of New York. In 2019, he was named a Fellow of the American Astronomical Society.