| John Henry Devitt | |
| Office1: | Ontario MPP |
| Term Start1: | 1905 |
| Term End1: | 1919 |
| Predecessor1: | William Rickard |
| Successor1: | William John Bragg |
| Constituency1: | Durham West |
| Party: | Conservative |
| Birth Date: | 1 February 1851 |
| Birth Place: | Cartwright Township, Canada West |
| Death Place: | Cartwright Township, Ontario |
| Occupation: | Civil servant |
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 married Elizabeth Watson on June 1, 1881.[1] He was a prominent member in the Orange Order. He died in 1940 and was buried at St. John's Cemetery in Blackstock.[2]