William Bigler was an American politician from Pennsylvania who served as a Democrat as the 12th governor of Pennsylvania from 1852 to 1855 and as a member of the United States Senate for Pennsylvania from 1856 to 1861. His older brother, John Bigler, was elected governor of California during the same period. As of 2023, he is the last Democratic incumbent to lose reelection as Governor of Pennsylvania.

John Bigler was an American lawyer, politician and diplomat. A Democrat, he served as the third governor of California from 1852 to 1856 and was the first California governor to complete an entire term in office, as well as the first to win re-election. His younger brother, William Bigler, was elected governor of Pennsylvania during the same period. Bigler was also appointed by President James Buchanan as the U.S. Minister to Chile from 1857 to 1861.