Knockboy (Irish: Knock Buí meaning Yellow Hill), commonly referred to as Ballygunner (Irish: Baile Mhic Gonair), is a suburb and formerly a village on the outskirts of Waterford City, Ireland.

It is within the dual parishes of St. Mary's and St Joseph and St. Benildus.

The old village of Knockboy consisted of an old 18th-century church, 19th-century schoolhouse, a row of cottages and a small pub at the base of the hill.

In the early 1990s, the cottages were demolished and new council houses were built at the site.

In the 2000s, a new housing estate was built adjoining the original village, in practise making it a suburb of Waterford City.