William Seymour may refer to:
- William Seymour (MP for Herefordshire) (died 1391), MP for Herefordshire (UK Parliament constituency)
- William Digby Seymour (1805âÂÂ1872), MP for Kingston-upon-Hull
- William Digby Seymour (1822âÂÂ1895), QC, lawyer and poet, MP for Sunderland and Somerset
- William H. Seymour (1840âÂÂ1913), American politician
- William J. Seymour (1870âÂÂ1922), American Pentecostal minister
- William Kean Seymour (1887âÂÂ1975), British writer
- William Seymour Jr. (1818âÂÂ1882), American banker who twice served as president of the New York Stock Exchange
- William Seymour (Congressman) (1775âÂÂ1848), US representative from New York from 1835 to 1837
- William Seymour (British Army officer, born 1664) (1664âÂÂ1728), lieutenant-general, MP for Cockermouth, Totnes and Newport (Isle of Wight)
- William Seymour, 2nd Duke of Somerset (1588âÂÂ1660)
- William Seymour, 3rd Duke of Somerset (1652âÂÂ1671)
- William Seymour Tyler (1810âÂÂ1897), American historian
- William Henry Seymour (1829âÂÂ1921), British Army officer
- Lord William Seymour (British Army officer) (1838âÂÂ1915), senior British Army officer