Sean Elsbernd is a fourth-generation San Franciscan. While a student at Claremont McKenna College, Elsbernd participated in the Washington D.C. Semester program, interning for Congressman Tom Lantos (D-CA). Additionally, he worked at the Rose Institute of State and Local Government, serving as assistant student manager during his senior year.
Upon graduating from CMC, Elsbernd attended the University of California Hastings College of the Law in San Francisco, graduating in 2000, and was subsequently admitted into the California Bar in December 2000.
In January 2001, San Francisco Supervisor Tony Hall named Elsbernd as his Chief of Staff. In January 2004, San Francisco Mayor Gavin Newsom appointed Elsbernd as his Liaison to the Board of Supervisors. To fill the vacancy left upon Supervisor Hall's resignation, Mayor Newsom appointed Elsbernd to finish the remainder of Hall's term on the San Francisco Board of Supervisors on August 5, 2004. Elsbernd then earned his own four-year term in the November 2, 2004 election.