Mynydd Tal-y-Mignedd is a peak on the Nantlle Ridge in Snowdonia, north Wales. It is located at the centre of the ridge, and is a subsidiary summit of Trum y Ddysgl.
The summit is crowned by a large stone obelisk, put up to commemorate Queen Victoria's Diamond Jubilee. A fine arete links it to its parent, Trum y Ddysgl, while a col links it to the next summit eastwards along the ridge, Craig Cwm Silyn.