| Barony of Upper Ossory | |
| Creation Date: | 11 June 1541 9 August 1794 |
| Remainder To: | First baron's heirs male of the body lawfully begotten |
| Extinction Date: | 13 February 1818 |
| Former Seat: | Cullahill Castle Tentore, County Laois Fermyn Woods Hall, Northamptonshire Ampthill Park, Bedfordshire |
| Motto: | Fortis sub forte fatiscet ("The strong will yield to the strong") |
Baron Upper Ossory was a title in the Peerage of Ireland. It was created on 11 June 1541 for Barnaby Fitzpatrick. This was in pursuance of the Surrender and regrant policy of King Henry VIII. Under the policy, Gaelic chiefs were actively encouraged to surrender their lands to the king and then have them regranted (returned) under a royal charter if they swore loyalty to him. Those who surrendered were also expected to speak English, wear English-style dress, remain loyal to the Crown, pay a rent and follow English laws and customs, abjure the Roman Catholic Church, and convert to Henry's new Anglican Church.[1]
The second Baron, also named Barnaby, was raised at Henry's court, as a companion for the future King Edward VI. Edward, who had few friends, became deeply attached to young Barnaby, and their later letters testify to their warm and lasting friendship.[1]
Upper Ossory was the northern third of the formerly larger Kingdom of Osraige.
The title was re-created on 9 August 1794 for the second Earl of Upper Ossory. On his death in 1818, both titles became extinct.