Mark Leno is a United States politician, representing California's 13th Assembly district, which consists of the eastern portion of San Francisco. He was elected in 2002 and is one of the first two openly gay men to serve in the Assembly. Leno previously served as a member of the San Francisco Board of Supervisors between 1998 and 2002 after being appointed by Willie Brown. Leno is the owner of Budget Signs Inc., a small business.

In 2007, he announced his candidacy to run for California's 3rd State Senate district against incumbent Carole Migden. One year later, former Assembly member Joe Nation entered the race. All three are Democrats and will face each other in the June 2008 Democratic primary.