James Blackwell may refer to:
- James Blackwell (basketball) (born 1968), American basketball player
- James Blackwell (rugby union) (born 1995), New Zealand rugby union player
- James Bartholomew Blackwell (1763–1820), Irish mercenary and French Army officer
- James DeRuyter Blackwell (1828–1901), author and poet of the American Civil War era
- James Eustace Blackwell (1865–1939), American architect, primarily in the Northwest