In the most recent (2006-2008) ranking of American philosophy departments by The Philosophical Gourmet, the Columbia University Department of Philosophy is ranked 10th. More generally, in the English-speaking world it was ranked 11th. It has particular strength in topics of: Philosophy of mind, political philosophy, philosophy of law, philosophy of biology, philosophy of social sciences, 17th-century early modern philosophy, and 20th-century continental philosophy.
Enrolled graduate students are able to take courses offered at City University of New York, which is a few blocks away, and at New York University. The philosophy departments of these universities naturally have close relations.
A short list of department faculty:
David Albert, specializing in philosophy of physics and philosophy of science.
John Collins, specializing in metaphysics, epistemology, and decision theory.
Lydia Goehr, specializing in philosophy of music, aesthetics, critical theory, philosophy of history, and 19th and 20th Century Philosophy.
Philip Kitcher, specializing in philosophy of science, biology, and mathematics.
Carol Rovane, specializing in metaphysics, philosophy of language, philosophy of mind. In history of philosophy: Descartes, Kant, the pragmatists.
Achille Varzi, specializing in logic and metaphysics.
Katja Vogt, specializing in ancient philosophy and ethics.