The Diocese purchased Garbally Court (built in 1819) and estate from the trustees of the Earls of Clancarty for £6,750 in 1922.

[4] Bishop John Kirby taught mathematics and coached the senior rugby team at the school in the late 1960s,[6] and was later appointed as president and principal of the college in September 1979.

[8][9] A consultation process began in early 2023 for Garbally College and Ardscoil Mhuire regarding the future of Catholic secondary school provision within Ballinasloe, conducted by their patrons the Diocese of Clonfert and the Catholic Education an Irish Schools Trust (CEIST).

Garbally offers all the mandatory subjects, along with woodwork, metalwork, home economics, technical graphics, business studies, design & communication and music.

[13][14] Garbally College is known for its sporting tradition in rugby union, hurling, Gaelic football and soccer.