William Harrington may refer to:

• William J. Harrington, politician in Manitoba, Canada
• William F. Harrington (1920–1992), American biochemist
• William D. Harrington (1832–1904), Nova Scotia politician
• William Harrington (Irish cricketer) (1869–1940), Irish cricketer
• William Harrington (English cricketer) (1915–1988), English cricketer
• William Harrington (knight) (died 1440), English knight
• William Harrington (priest) (1566–1594), English Jesuit priest and Martyr
• William Harrington (MP) (died 1488), Member of Parliament for Lancashire
• William Harrington (artist) (born 1941), Irish artist
• Bill Harrington (broadcaster) (1926–1998), American sportscaster, children's television host, and news reporter
• Bill Harrington (baseball) (1927–2022), American baseball pitcher
• Bill Harrington (Australian footballer) (born 1942), Australian rules footballer for Footscray
• Bill Harrington (Irish footballer), Irish international footballer

• Billy Herrington (1969–2018), pornographic film actor and model