| Y Gyrn | |
| Elevation M: | 619 |
| Prominence M: | 24 |
| Parent Peak: | Pen y Fan |
| Listing: | sub Hewitt, Nuttall |
| Language: | Welsh |
| Location: | Powys, Wales |
| Range: | Brecon Beacons |
| Grid Ref Uk: | SO012215 |
| Topo: | OS Landranger 160 |
Y Gyrn is a top of Pen y Fan in South Wales, situated in the Brecon Beacons National Park. Tommy Jones' Obelisk is found in between the summit and Corn Du.
The summit is a boggy mound overlooking the A470 and the Storey Arms. It is marked by a pile of stones.[1]