| Country: | Wales |
| Official Name: | Llandwrog |
| Coordinates: | 53.079°N -4.314°W |
| Static Image Name: | Canol Pentref Llandwrog Village Centre - geograph.org.uk - 607666.jpg |
| Static Image Caption: | Llandwrog village centre |
| Population: | 2,539 |
| Population Ref: | (2011) |
| Community Wales: | Llandwrog |
| Unitary Wales: | Gwynedd |
| Constituency Welsh Assembly: | Arfon |
| Constituency Westminster: | Arfon |
| Post Town: | CAERNARFON |
| Postcode District: | LL54 |
| Postcode Area: | LL |
| Dial Code: | 01286 |
| Os Grid Reference: | SH450560 |
Llandwrog (; Welsh language: meaning 'The church of Saint Twrog') is a village and community in Gwynedd, north-west Wales, most notable for the presence of the headquarters of Welsh record label Sain and the site of Caernarfon Airport. It has a population of 2,466,[1] increasing to 2,539 at the 2011 Census.[2] The community includes the villages of Groeslon, Carmel, Y Fron, Dinas Dinlle, and Cilgwyn. As suggested by the village name, the parish church is dedicated St Twrog.[3] It was the base of the first ever Sea and Mountain Rescue team, and includes the estate of Glynllifon.
RAF Llandwrog was a training airfield during World War II, and was later used as a weapons storage facility. It had a key role in Operation Sandcastle, where a large quantity of Nazi Tabun weapons were stored prior to eventual disposal at sea.