Tre-pit is located in the county of South Glamorgan, Wales, four miles north-west of the town of Llantwit Major, 21 miles south-east of the major city of Swansea, 17 miles west of Cardiff, and 148 miles west of London. Tre-pit lies three miles south of the Mid Glamorgan border, and was historically in the county of Glamorgan. Tre-pit falls within the unitary authority of Bro Morgannwg - the Vale of Glamorgan. It is in the CF71 postcode district.


Tre-pit is in the ceremonial county of South Glamorgan, the historic county of Glamorgan, and the administrative county of Bro Morgannwg - the Vale of Glamorgan.
| Ceremonial County | South Glamorgan |
|---|---|
| Historic County | Glamorgan |
| Administrative County | Bro Morgannwg - the Vale of Glamorgan |
Tre-pit is situated roughly centrally between the southernmost and northernmost extremities of South Glamorgan, and towards the westernmost extremity of South Glamorgan.

The nearest postcode to the centre of Tre-pit is CF71 7QL.
Tre-pit is situated towards the southernmost extremity of the CF71 postcode district, and towards the westernmost extremity of the CF71 postcode district.

The centre of Tre-pit is located at position 51.43777° latitude and -3.55934° longitude.
| Latitude | 51.43777° |
|---|---|
| Longitude | -3.55934° |
The centre of Tre-pit is located at the grid reference easting 291711 and northing 172129 within the British National Grid (OSGB36) system.
| Easting | 291711 |
|---|---|
| Northing | 172129 |
Position of Tre-pit relative to nearby towns. Distance is measured from the centre of Tre-pit to the centre of the town.
Position of Tre-pit relative to nearby cities. Distance is measured from the centre of Tre-pit to the centre of the city.