| Country: | England |
| Map Type: | Cornwall |
| Coordinates: | 50.3768°N -4.9816°W |
| Official Name: | Trewinnion |
| Civil Parish: | St Enoder |
| Unitary England: | Cornwall |
| Lieutenancy England: | Cornwall |
| Region: | South West England |
| Constituency Westminster: | North Cornwall |
| Post Town: | NEWQUAY |
| Postcode District: | TR8 |
| Postcode Area: | TR |
| Dial Code: | 01872 |
| Os Grid Reference: | SW881573 |
Trewinnion is a hamlet in mid Cornwall, England, United Kingdom. It is situated north of the village of Summercourt about four miles (6.5 km) south-west of Newquay. The settlement consists of a large farmstead and several cottages. Trewinnion was formerly a manor in the ancient parish of St Enoder which was mortgaged in the 1850s by the Mohun family.