Mary O'Leary

Mary O'Leary may refer to:

• Mary O'Leary (producer), American soap opera producer
• Mary O'Leary (camogie), Irish former camogie player
• Mary O'Leary (Big Brother), Irish reality show contestant
• Liz Truss (born 1975), British former Prime Minister, whose birth name was Mary and is married to Hugh O'Leary