| Country: | Wales |
| Constituency Welsh Assembly: | Ynys Môn |
| Coordinates: | 53.324°N -4.459°W |
| Official Name: | Llantrisant |
| Unitary Wales: | Anglesey |
| Constituency Westminster: | Ynys Môn |
| Post Town: | HOLYHEAD |
| Postcode District: | LL65 |
| Postcode Area: | LL |
| Dial Code: | 01407 |
| Os Grid Reference: | SH363835 |
Llantrisant (; Welsh for "Parish of the Three Saints") is a hamlet in Anglesey, Wales. It is in the community of Tref Alaw.[1]
Its parish church is dedicated to Saints Afran, Ieuan, and Sanan.[2] The parish's former church is now a protected building. Browne Willis and Sabine Baring-Gould[3] considered "Afran" to be a corruption of Afan, a saint of Ceredigion and Brecknockshire. (The 16th-century Peniarth MS 147 concurs, listing the church as dedicated to "Sannan and Afan and Evan".[3]) St Afan was related to the Cuneddan dynasty of Gwynedd and was claimed as an ancestor by a 10th-century Ieuan martyred by Viking raiders.[4]