William Gregg
William Gregg may refer to:
- William Gregg , British First World War Victoria Cross recipient
- William Gregg , founder of the pioneer Graniteville, South Carolina textile mill
- William Gregg, Australian tennis player in 1907 Australasian Championships
- William Gregg, founder of the New Zealand company Gregg's
- William Gregg , Scottish clerk and spy
- Bill Gregg, Australian rules footballer
- William O. Gregg, American bishop
- William Gregg , Canadian theologian and clergyman; Professor of Apologetics