Tomasz "Tomek" Bartoszyński (born 16 May 1957) is a Polish-American mathematician who works in set theory.

In 1984, he defended his Ph.D. thesis Combinatorial aspects of measure and category; his advisor was Wojciech Guzicki.

From 1986 onward, he worked in the United States: he taught at the University of California in Berkeley and Davis.

In 1990-1991, he visited the Hebrew University of Jerusalem as a fellow of the Lady Davis foundation, and in 1996/97 he visited the Free University of Berlin as a Humboldt fellow.

His wife, Joanna Kania-Bartoszyńska, is the NSF program director for topology and geometric analysis.