• Conor Sinnott (born 1986), a professional footballer
• Declan Sinnott, an Irish-born musician and producer
• Edmund Ware Sinnott (1888–1968), an American botanist and textbook author
• Herbert Arthur Sinnott (1871–?), the 21st mayor of Calgary, Alberta
• Joe Sinnott (born 1926), an American comic book artist
• John Sinnott (1829–1896), an Irish recipient of the Victoria Cross
• Kathy Sinnott (born 1950), a disability rights campaigner and politician representing Ireland
• Lee Sinnott (born 1965), an Irish ex-professional footballer
• Lillian Sinnott (1890–1914), an American actress of the stage
• Nicholas J. Sinnott (1870–1929), a US Representative from the state of Oregon
• Paul Sinnott, an English drummer
• Will Sinnott (1960–1991), a Scottish musician and songwriter
• William Sinnott (1886–1965), an American detective and Congressional Gold Medal recipient

See also

• Sinnott Township, Minnesota