A number of people have been called John Kay:

• John Kay (flying shuttle) (1704–1780), English inventor of textile machinery, notably the flying shuttle
• John Kay (spinning frame) (17??–17??), English developer of textile machinery, notably the spinning frame (not the same as John Kay immediately above)
• John Kay (caricaturist) (1742–1826), Scottish caricaturist
• John Kay (Medal of Honor), American Indian Wars soldier and Medal of Honor recipient
• Sir John Kay (judge) (1943–2004), British High Court judge
• John Kay (musician) (1944– ), musician and lead singer of Canadian rock band Steppenwolf
• John Kay (poet) (14th century), English poet laureate
• John Kay (economist) (1948– ), Scottish economist, Financial Times columnist and author
• John Kay (journalist) (1944– ), British Journalist on Rupert Murdoch's The Sun

Also:

• Johnny Kay, lead guitarist for Bill Haley and His Comets from 1961 to 1967

John Kay