Billie Tsien received her undergraduate degree in Fine Arts from Yale in 1971 and her M. Arch. from UCLA in 1977. In the period from 1971 - 1975 she was a painter and teacher. She has taught at The Southern California Institute of Architecture, Parsons, Yale, Harvard GSD and the University of Texas at Austin. She has worked with Tod Willliams since 1977 and they have been in partnership since 1986. They are married and have a 15-year-old son.

Widely published works include The Spiegel Pool House, Feinberg Hall at Princeton University, The Whitney Museum of American Art Downtown Branch in New York City and the Neurosciences Institute in LaJolla, California. She and Tod Williams have completed Hereford College, a 525 person dormitory and dining facility at the University of Virginia. Additional completed projects include several residences in New York City, Southampton and Phoenix, a major addition to the Phoenix Art Museum, a science building and aquatic center for The Emma Willard School in Troy, New York, the Natatorium at the Cranbrook School and the Neurosciences Institute in La Jolla, California which has won a National AIA Honor Award.

Currently, the office is working on The Museum of Folk Art in New York City, and The Students Arts Center at Johns Hopkins University in Baltimore.

Billie Tsien has a particular interest in work that bridges art and architecture. She has served on various panels for the National Endowment for the Arts, the Percent for Art Jury for the Cities of New York and Seattle, and is on the board of the Public Art Fund, the Architectural League and the Municipal Art Society in New York. She is the recipient with Tod Williams of the Brunner Award from the American Academy of Arts and Letters, the Medal of Honor from the New York City AIA, and the Chrysler Award for Design Innovation.