The Missionary Society of St. Columban, commonly known as the Columbans, is a missionary Catholic society of apostolic life of Pontifical Right founded in Ireland in 1917 and approved by the Vatican in 1918. Initially it was known as the Maynooth Mission to China. Members may be priests, seminarians or lay workers. Fr John Blowick, one of the two founders of the Society, also founded the Missionary Sisters of St. Columban to share in their work. The society is dedicated to St. Columbanus. The current international headquarters is in Hong Kong.

Columbanus was an Irish missionary notable for founding a number of monasteries after 590 in the Frankish and Lombard kingdoms, most notably Luxeuil Abbey in present-day France and Bobbio Abbey in present-day Italy.