Trinity Gask is a parish, which lies in Perth and Kinross Council Area, some 3 miles (5 km) north of Auchterarder and 6 miles (9 km) southeast of Crieff in Perth and Kinross.
It is located in the old county of Perthshire, which disappeared following the Local Government (Scotland) Act 1974.
The parish has an area of 23.3 sq. km (9 sq. miles). Trinity Gask has 7 neighbouring parishes; namely Auchterarder, Blackford, Crieff, Dunning, Findo Gask, Madderty and Muthill.