Heather O'Mahony joined Bonhams in 2007 and currently serves as its Regional Representative of Washington, based in Seattle. In this role O'Mahony facilitates fair market valuations of collections for private clients and public institutions, as well as for the Trust & Estate community. She oversees consignments and bid placement and regularly conducts valuation days with visiting experts.
She was initially a Representative at an international auction house in Seattle. In 2005, she was accepted into a prestigious internship programme at the Peggy Guggenheim Museum in Venice, Italy. Returning to Seattle in 2006, O'Mahony joined the Conservation Department at the Seattle Art Museum during the museum's expansion of its downtown facilities and new Olympic Sculpture Park.
O'Mahony received her undergraduate degree in Art History from the University of Washington and also studied at Richmond University in Florence, Italy, specialising in Italian Renaissance and Italian language.
She is active in the nonprofit sector, currently serving on the Auction Committee for Pratt Fine Arts Centre, and she is a member of the Seattle Art Museum supporters.