Mark Sainsbury is a London philosopher who has worked in the areas of philosophical logic, philosophy of language, reference, and the philosophy of Russell and Frege.

His first book was on Russell (Routledge, 1979). His latest book Departing From Frege (2002) is on the philosophy of Frege. He has also written about the paradoxes (Paradoxes Cambridge, 1988, 1995). He was editor of Mind from 1990 to 2000.