John Henry Devitt (February 1, 1851 – June 14, 1940) was an Ontario political figure.
He represented Durham West in the Legislative Assembly of Ontario from 1905 to 1919 as a Conservative member.
He was born in Cartwright Township, Canada West, the son of Thomas Devitt and Jane McKee.
He was a member of the township council from 1882 to 1890, serving as reeve in 1896 and county warden in 1899.
He died in 1940 and was buried at St. John's Cemetery in Blackstock.