Fan Fraith is a top of Fan Gyhirych in the Fforest Fawr section of the Brecon Beacons National Park in the county of Powys, south Wales.

Its summit is at a height of 2192 feet or 668 m. It lies within Fforest Fawr Geopark.

Sandstones of the overlying Plateau Beds Formation occur in the summit area as do beds of the Grey Grits Formation - both are assigned to the upper Devonian.

The Plateau Beds sandstones occur across the whole southern aspect of the mountain and are often present as boulder fields,a result of periglacial activity.

A private vehicular track which runs over the southeastern shoulder of neighbouring Fan Gyhirych affords the easiest and most commonly used ascent of Fan Fraith.