Thomas, Tom, or Tommy Douglas may refer to:

• Thomas Douglas (American judge) (1790–1855), Florida Supreme Court justice
• Thomas Douglas, 5th Earl of Selkirk (1771–1820), founder of the Red River Colony
• Thomas Monteath Douglas (1787–1868), officer of the Bengal Army of the East India Company
• Tom Douglas (chef) (born 1958), American chef, restaurateur and writer
• Tom Douglas (footballer) (1910–1943), Scottish footballer
• Tom Douglas (songwriter) (born 1953), American songwriter
• Tommy Douglas (1904–1986), premier of Saskatchewan and leader of the New Democratic Party of Canada
• Tommy Douglas (clarinetist) (1911–1965), American jazz clarinetist
• Tommy Douglas Collegiate, a high school in Saskatoon, Saskatchewan, Canada

• Thomas Douglas Guest (1781–1845), British painter