Ballybritt (Irish: Baile an Bhriotaigh) is a barony in County Offaly (formerly King's County), Ireland.

Ballybritt derives its name from Ballybritt Castle (near Roscrea) and the townland of Ballybritt (Irish Baile an Bhriotaigh, "settlement of the Welshman").

Ballybritt is located in south County Offaly, west of the Slieve Bloom Mountains.

Ballybritt was included in the northern part of the territory of the Éile (Ely), and in early times was a crossroads for the ancient borders of the kingdoms of Mumu, Mide and Laigin.

Below is a list of settlements in Ballybritt:

• Birr
• Cadamstown
• Clareen
• Crinkill
• Kinnitty