James Earl Baumgartner (1943) is an American mathematician active in set theory, mathematical logic and foundations, and topology. He is an emeritus professor at Dartmouth College.
Baumgartner received his PhD in 1970 from the University of California, Berkeley for a dissertation entitled "Results and Independence Proofs in Combinatorial Set Theory". His advisor was Robert Vaught. [MathGenealogy|id=22587]
One of Baumgartner's result is the consistency of the statement that any two -dense sets of reals are order isomorphic (a set of reals is -dense if it has exactly points in every open interval). With Andras Hajnal he proved the result that the partition relation holds for