John Farrell may refer to:
- in sports
- Other people
- John Farrell (bishop) (1820–1873), Canadian Roman Catholic bishop
- John Farrell (Australian poet) (1851–1904), Australian journalist and poet
- John Farrell (poet) (1968–2010), American poet and composer
- John Farrell (VC) (1826–1865), Irish Victoria Cross winner
- John A. Farrell, American reporter, and biographer
- John H. Farrell (1919–1995), New York politician
- John S. Farrell (1880–1938), mayor of Green Bay, Wisconsin
- John J. Farrell (1872–1946), Dairy and Food Commissioner of Minnesota
- John J. Farrell (Lord Mayor of Dublin) (1871–1954), Lord Mayor of Dublin
- John Farrell (architect) (1868–1938), New Zealand architect and politician