John Francis Seymour Jr.[1][2] (born December 3, 1937) is an American retired politician who served as a United States senator from California from 1991 to 1992.

A member of the Republican Party, he was appointed to continue Pete Wilson's term but lost the special election to finish it to Democratic nominee and former San Francisco mayor Dianne Feinstein.

Seymour was also the last U.S. senator from southern California until Alex Padilla took office on January 20, 2021, replacing Kamala Harris when she was inaugurated as vice president of the United States.

Seymour's appointment lasted until the 1992 special election to select a replacement who would serve until the normal expiration of Wilson's term in 1995.

After his Senate term, Seymour was director of the California Housing Finance Agency for two years,[6] and later was CEO of the nonprofit Southern California Housing Development Corporation and on the boards of directors of several housing-related companies including IndyMac Bank, Orange Coast Title Insurance, Los Angeles Federal Savings Bank, and Irvine Apartment Communities.