**Andrej Bauer** (born May 11, 1971) is a Slovenian mathematician at the University of Ljubljana where he holds the title Professor of Computational Mathematics. He does research in logic, constructive and computable mathematics, category theory, and semantics of programming languages. He got his Ph.D. at Carnegie Mellon University in 2000 under the supervision of Dana Scott.

From September to December 2012 Bauer was a visiting scholar at the Institute for Advanced Study where he was invited to join the *Special Year on Univalent Foundations of Mathematics*. He contributed significantly to this project and helped to produce the document called 'The HoTT Book' which summarized much of the work done during the special year in the new field of Homotopy type theory.

Bauer is a supporter of using web-based software systems such as GitHub to promote collaborative work by mathematicians–the six-hundred-page HoTT Book being a notable example.