Castlederg St Eugene's (Irish: Caisleán na Deirge Naoimh Eoghain) is a Gaelic Athletic Association club. The club is based in Castlederg in County Tyrone, Northern Ireland.

The club concentrates on Gaelic football, while Mná Na Deirge provides for ladies Gaelic football.

The club was formed in 1975 under the name Naomh Eoghan Caisleán na Deirge C.L.G and has been in continuous existence ever since.

For the most part of the club's existence they have played their adult football at Junior level. However they were promoted to Intermediate football in 1980 and remained at that level until 1983. They were again successful at gaining promotion in 1989 and stayed in the Intermediate grade until 1993. In 2001 they won their first adult title when their Reserve team annexed the Junior Reserve Championship, beating Newtownstewart at Drumquin.

The senior team competed in Division 3 of the Tyrone All-County Football League and in the Tyrone Junior Football Championship up until they gained promotion in 2016 by finishing top of the League, just a single point above Tattyreagh, after a victory over Glenelly (1-14 to 1–8) on the final day of the season. Unfortunately the club found life in Division 2 difficult, finishing second from bottom with only 8 League points after only 3 league wins and 2 draws.

In 2018 the club returned to junior football, which is where they have continued to play their football since.

In 2016, under the management of Dermot Corry, the club lifted their first ever title at adult level when they lifted the Division 3 All County League.

• Tyrone All-County League Division 3: (1)
  • 2016

• John Lynch - Tyrone Senior Footballer (1980 - 1992) and 1986 All Star.
• Aiden Lynch - 1997 and 1998 Tyrone Minor. All-Ireland Minor winner 1998 and All-Ireland Minor Final Man of the Match 1998.
• Shannon Lynch - 2005 - present, Tyrone senior ladies' football (goalkeeper).

• Castlederg St Eugene's GAC Website