Daniel or Dan O'Brien may refer to:
Politicians and nobles
- Daniel O'Brien, 1st Viscount Clare (1577âÂÂ1663), MP for County Clare, younger son of Connor O'Brien, 3rd Earl of Thomond
- Daniel O'Brien, 3rd Viscount Clare (fl. 1670âÂÂ1691), son of Connor O'Brien, 2nd Viscount Clare
- Daniel O'Brien, 4th Viscount Clare (died 1693), son of Daniel O'Brien, 3rd Viscount Clare
- Daniel O'Brien (Jacobite) (1683âÂÂ1759), Irish Jacobite soldier and diplomat
- Daniel Pitt O'Brien (1900âÂÂ1957), Secretary of State of West Virginia
Sportspeople
Athletes
Coaches / executives
Writers / journalists
See also