The University of Washington Mathematics Department is one of the top 15 public university research math departments in the US, and research is one of the core missions the department.  The department's own strong research faculty is joined in any given year by several talented newly graduated postdocs and numerous distinguished visitors from other universities.  The department's endowed Milliman fund supports a variety of medium-term visitors, as well as the Milliman lectures, an annual series of expository lectures by a world-renowned mathematician on a current research topic.

UW  is one of the sponsoring universities of the Mathematical Sciences Research Institute (MSRI), a mathematical "think tank" in Berkeley, California, dedicated to furthering research in the mathematical sciences through year-long programs and special workshops.  As a sponsor, UW benefits from frequent visits by MSRI mathematicians, and from opportunities to send participants to special MSRI programs.  For example, MSRI sponsors a summer program for graduate students each year, which two UW students are invited to attend free of charge.

In 2000, the UW became a full participating member of the new Pacific Institute for the Mathematical Sciences (PIMS), an international mathematics research institute based in Vancouver, BC.  PIMS is dedicated to promoting all aspects of the mathematical sciences, including research, education, and technology transfer.  This US-Canada collaboration is expected to open up a whole new era of scientific collaborations between the mathematical communities of the two countries, and hopes to serve the mathematical sciences community as a catalyst in communicating and disseminating mathematical ideas and creating strong mathematical partnerships and links within Canada and organizations in other countries, with a focus on the nations of the Pacific Rim.  The University of Washington joins the five founding partners of PIMS: The University of Alberta, The University of British Columbia, The University of Calgary, The University of Victoria, and Simon Fraser University.

The Mathematics Department also has close ties with the Theory Group at Microsoft Research.