The Sugar Loaf (Welsh: Mynydd Pen-y-fâl) is a hill situated two miles (3.2 km) north-west of Abergavenny in Monmouthshire, Wales, within the Brecon Beacons National Park.

A southern foothill of Sugar Loaf, Y Graig, was discovered in the 1990s to be the site of prehistoric flint tools dating from the Mesolithic, Neolithic and Bronze Ages.

In common with the rest of the Black Mountains, the hill is formed from Old Red Sandstone which was laid down largely during the early part of the Devonian Period.

A vineyard, producing Sugar Loaf wines, is situated at Dummar Farm at the foot of the mountain on south facing slopes near Abergavenny.

[6] The view from the summit[7] covers the Black Mountains to the north, the Cotswolds to the east, as far as the Brecon Beacons including Pen y Fan and Corn Du to the west and the Bristol Channel to the south.