The club was formed in 1968 when Peterswell and Kilchreest amalgamated. Peterswell had enjoyed early success in the late 1800s and early 1900 with them winning the Galway Senior Hurling Championship title in 1889, 1898, 1899, 1900, 1904, 1905 and 1907. They were a major force in Galway GAA throughout this period. The both adjoining parishes were associated with hurling since its foundation but due to emigration and lack of numbers the parishes decided to amalgamate. The first year in competitive hurling was a successful one. The under 14 team brought the club its first success by winning the county title. The team would follow this up by winning the county under 16 title in 1970. Construction began on their current clubhouse which is located on the main Gort to Loughrea Road in 1976. That along with a brand new pitch were finally officially opened in 1983 by the President of the GAA, the late Paddy Buggy. In 1978 another milestone was reached when the club was promoted to senior ranks after reaching the county intermediate final, however they were defeated by close neighbours Kilbeacanty. Following the promotion to senior ranks the club endured a chequered existence in senior hurling. Having been relegated on a number of occasions they secured promotion with Intermediate Championship victories in 1996 and 2004. They were crowned Galway Senior Champions for the first time in 2012 by defeating Loughrea in the final on a scoreline of 3–11 to 2–11 in Pearse Stadium. They followed this up by taking the All-Ireland Senior Club Hurling Championship by defeating Kilcormac-Killoughy on St Patricks Day. In 2016, the secured a second Galway Senior Hurling Championship by beating Gort in the final on a scoreline of 1–11 0–10.
All Ireland victory 2013
Path to county final
In the quarter finalsSt Thomas's were 2–20 to 0–10 winners over Galway club Castlegar. Centre-forward Conor Cooney lead the way scoring 1–6. In the Semi-final St Thomas's met county champions Gort. St Thomas's led at half time however Gort rallied, scoring two late points to secure a replay. Gort's Aidan Harte scored the equalising point from a 65 in the third minute of additional time. They overcame Gort in the replay in Kenny Park Athenry. St Thomas's won their first senior county title in November 2012 defeating Loughrea in the final.
Semi-final
They faced Antrim side and Ulster Champions Loughgiel Shamrocks in the All Ireland semi-final in Parnell Park. St. Thomas's were leading by four points in injury time. However, Liam Watson tipped over a twenty-metre free and scored a goal from a free in the last puck of the dramatic game to secure a draw for Loughgiel. St Thomas's were victorious in the replay played in Clones, winning on a scoreline of 0–15 to 0–7.
