Glyder Fach is a mountain in Snowdonia, north-west Wales, and is the second highest of the Glyderau and the sixth highest in Wales. Routes to the summit lead from Tryfan and Bristly Ridge to the north, via Glyder Fawr from Pen-y-Pass to the south, and along the Glyder ridge to the east, towards Capel Curig. It is a popular spot for climbers.
According to Sir Ifor Williams, the word "Glyder" derives from the Welsh word "Gludair", meaning a heap of stones.Situated near the summit is the Cantilever Stone, a large rock which from the correct angle appears to be precariously balanced, making it a popular place for photographs. Another notable feature, west of the summit, is Castell y Gwynt, (Castle of the Wind), a spiky rocky outcrop.