Kilcoo GAC was founded in 1906 although there were records of GAA being played there since the 1880s but a proper club wasn't formed until then. The club's first competitive match took place on 13 January 1907 against local team Liatroim (who were the first club formed in the county). The match ended Kilcoo 0-0 Leitrim 0-5. Kilcoo won their first Senior County Championship in 1917 defeating Killyleagh in the final. The club have won the championship on eight other occasions: 1922, the glorious "four in a row" 1925,1926,1927,1928,1932,1933 and 1937.
As of late Kilcoo ended their 72-year drought with a well-deserved and hard-battled victory over Loughinisland. They showed immense character to come from behind in the first half to win the match. Earlier in the day the Kilcoo Minor team also lifted the championship with an outstanding over-haul victory over Warrenpoint. It was a historical day for the magpies as they cemented their grip on Down football once again.
Kilcoo GAC is one of the most successful clubs in County Down today. The club has a camogie team, a ladies football team and football teams at Under-8, Under-10, Under-12, Under-14, Under-16, Minor, Seconds, Thirds, Under-21 and Senior Level. The Senior team compete in Division 1 and play in the Down Senior Football Championship. Kilcoo are regularly represented on Down GAA teams. In 2005 three Kilcoo players were on the Down Under 21 football team who reached the All-Ireland Final. In 2006 Kilcoo had a good run in the Down Senior Football Championship reaching the semi-finals. In their first round match they faced Division Two side Downpatrick in Castlewellan. In what would be a tough match Kilcoo prevailed on a scoreline of 1-10 to 1-7 with corner forward Sean Kelly scoring 0-3. Next up was Castlewellan in the quarter-final in Downpatrick. These two teams met at the same stage a year earlier with Castlewellan gaining the victory. This time Kilcoo won by seven points on a scoreline of 1-13 to 1-6. Conor Laverty came on as a substitute and scored a goal and two points. The semi-final was next and would be against Mayobridge who had won the last two championships. The Kilcoo players knew they were facing the best club team in Down and that they would be up against it. Kilcoo started brightly and scored a goal in the first ten minutes. However Mayobridge's experience more than anything else carried them through for the victory with the score 0-13 to 1-9. It was a cruel blow for Kilcoo but knew that they pushed the county champions to the limit. In the league Kilcoo finished in first place but were beaten well by Burren in the semi-finals of the Division 1 play-offs. In 2007 Kilcoo played Leitrim in the first round of the Down Senior Football Championship and defeated them after a replay. Kilcoo were beaten in the quarter finals by eventual finalists Longstone. The club reached the All County Division One League Final after defeating Burren after extra time in the semi-final. Kilcoo were defeated in the final by An Riocht on the scoreline of 3-7 to 1-10. Returning Australian Football League player Martin Clarke scored 2-1 for An Riocht in the final. The 2008 season started off against the team that beat Kilcoo in the League Final. This time Kilcoo earned an easy victory. Their next match saw them play Burren where they were defeated. Kilcoo finished second in the league table behind Mayobridge. In the Championship, Kilcoo's opponents were An Riocht again with Kilcoo running out comfortable winners on a scoreline of 3-15 to 0-3. Next up was Burren. The match was played in slippery conditions and Kilcoo were lucky to escape with a draw on a scoreline of 1-6 to 1-6. Paul Greenan grabbed the vital goal for Kilcoo. In the replay Kilcoo were well beaten. After the disappointing championship exit Kilcoo were able to focus on the league. After finishing second to Mayobridge, Kilcoo entered the play-offs. In the semi-final Kilcoo were up against Rostrevor under lights at Páirc Elser. Kilcoo gained a hard earned win with a 1-7 to 0-7 with Paul Devlin scoring 1-4. The final in Newry again was against county champions underdogs as "The Bridge" were looking to do the double. In an excellent display of football Kilcoo ran out easy winners in the end with the result 3-14 to 1-7. Paul Devlin was the star of the show again scoring 0-8. Captain Gerard McEvoy accepted the cup and dedicated the win to Arthur Morgan, club president who died the previous week. Kilcoo started their 2009 Down Senior Football Championship campaign with a tricky tie against local rivals Bryansford. After a hard working display Kilcoo came out on top winning 2-9 to 1-9. Next up was county champions Mayobridge in a waterlogged Hilltown pitch. Kilcoo went into this match as underdogs and rallied in the last five minutes to come from six points down to win 1-10 to 1-8. The semi final against Burren was very tense but Kilcoo prevailed on a scoreline of 0-12 to 0-10 with goalkeeper Stephen Kane saving a penalty in the first half. Kilcoo had now reached their first senior final since 1948 and had the chance to bridge a 72-year gap when they last won the title in 1937. Only Loughinisland stood in their way. Kilcoo settled in the second half and came out on top leaving Loughinisland scoreless in the second half also. Final score 2-9 to 1-4. When the final whistle blew the whole Kilcoo crowd invaded the pitch with a sea of black and white in a scene that sparked wild celebrations and that will go down as one of the most memorable moments in the club's history. Captain Gerard McEvoy collected the Frank O'Hare Cup while Anthony Devlin collected the Man of the Match award. The team arrived back home to Kilcoo that evening to a heroes welcome in front of a large crowd who assembled in the village. The team then ventured into their first ever Ulster Championship campaign with a meeting against St. Eunan's of Donegal. After a great team performance Kilcoo came out on top on a scoreline of 0-13 to 0-9. Their next opponents would be The Loup from Derry. Kilcoo played extremely well but were unable to hold on to the lead and the match ended Loup 1-12 Kilcoo 1-11. In November 2010, Kilcoo Minors retained their title as they over came Rostevor. Kilcoo were in a commanding position from the start and even late rally from Rostrevor's Caolan Mooney wasn't enough for Rostrevor. In the end Kilcoo running out easy winners, to gain back-to-back titles. Kilcoo won the minor championship for the 3rd year in a row beating Warrenpiont 1-12 to 0-10 and the senior team also won the League beating Mayobridge 2-16 to 1-06