John Farrell (2 June 1820 – 26 September 1873) was a Canadian Roman Catholic priest and Bishop of Hamilton, Ontario from 1856 to 1873.

Bishop Farrell was dedicated to establishing a solid separate Catholic school system.

By the end of his seventeen-year tenure as Bishop, twenty-six separate schools were functioning within the diocese.

The Honourable John Farrell's role as Bishop of the Diocese of Hamilton was cut short on September 26, 1873, when at the age of 53 he succumbed to peritonitis.

He was laid to rest in a vault beneath his cathedral, St. Mary's Church in Hamilton.