William Bigler (January 11, 1814 – August 9, 1880) was governor of Pennsylvania from 1852 to 1855, and later a U.S. Senator.

Bigler was born in rural Pennsylvania and received little formal education; he studied informally under his elder brother John Bigler (later governor of California), publisher of the Centre County Democrat newspaper. Bigler founded his own political newspaper, the Clearfield Democrat, in 1833, and later became wealthy in the lumber business. In the 1840s he served in the Pennsylvania senate, and he defeated incumbent governor William F. Johnston for the governor's seat in 1851. Although Bigler opposed slavery in principle, he supported the federal government's Fugitive Slave Act and the pro-slavery Kansas-Nebraska Act. He was defeated for a second term by James Pollock, the candidate of the newly formed Republican Party. Following his term as governor, he served in the United States Senate from 1856 to 1861.

|- style="text-align: center;" | width="30%" |Preceded by:
James Cooper | width="40%" style="text-align: center;" |United States Senator from Pennsylvania
1856–1861 | width="30%" |Succeeded by:
Edgar Cowan