District (pop., 2001: 47,735) and town (pop., 1991: 18,000), Northern Ireland.
Formerly in County Tyrone, the district was established in 1973. The area was ruled by the ancient O'Neill family (5th–16th centuries), passing to English rule after the flight of Hugh O'Neill in 1607. It was the site of sectarian violence in 1998, when a car bomb killed 29 people. Most of the land is grazed by dairy cattle or sheep, and the rivers contain salmon and trout. Omagh town, the district seat, is a market and light-manufacturing centre.