John Barnewall

• John Barnewall, 3rd Baron Trimlestown, Irish nobleman, judge and politician
• John Barnewall , Irish Franciscan friar and scholar
• Sir John Robert Barnewall, 11th Baronet, of the Barnewall baronets
• John Barnewall , Irish landowner, barrister, judge and Recorder of Dublin
• John Thomas Barnewall, 15th Baron Trimlestown, Irish landowner