Abby Brethauer is in her third season as the associate head coach of the Tufts University men's and women's swimming teams.

During her first year with the Jumbos (2018-19), Tufts enjoyed great combined success with the men finishing 10th nationally and the women earning a 16th-place NCAA finish that was the team's best since 1990. The Jumbos also had their first NCAA men's champion swimmer since 1982 (Roger Gu in the 50 free) and their first New England Small College Athletic Conference  (NESCAC) champion women's swimmer since 2014 (Amy Socha in the 200 butterfly). For 2019-20, both teams were the runner-up at the conference championships. Twelve members of the women's team and 10 from the men qualified to compete at NCAA's before the meet was canceled due to COVID.

Brethauer was previously head coach of the men's and women's swimming programs at the University of Mary Washington for the past eight seasons. At Tufts she replaced Nancy Bigelow, who retired in 2018 following a 43-year career as a swimming coach including 36 seasons at Tufts.

At Mary Washington since 2010, Brethauer received six women's Coach of the Year honors and four with the men's team in the Capital Athletic Conference. While there she also served on the Presidential Task Force for Diversity & Inclusion and was the Athletic Department's Community Service Coordinator from 2013-18.

Originally from Bedford, New Hampshire, Brethauer was an assistant coach at Columbia University from 2004-10. In addition to time as an assistant coach at Hamilton College, she also has familiarity with the NESCAC as the head coach of the Bates College Swim Camp since 2008.

As a competitor, Brethauer was a member of three NCAA championship teams at Kenyon College, where she was team captain for 2001-02. A former NCAA DIII national record holder and 13-time All-American, Brethauer graduated from Kenyon in 2002. She earned a Master's Degree in Kinesiology at Columbia University's Teacher's College in 2009.