Coordinates: 55°01′19″N 7°19′52″W / 55.022°N 7.331°W
St Columb's College is a Roman Catholic boys' grammar school in Derry, Northern Ireland and, since 2008, a specialist school in Mathematics and Computing. It is named after Saint Columba, the missionary monk from County Donegal who founded a monastery in the area.
St Columb's College was established in 1879 on Bishop Street (now the site of Lumen Christi College), but later moved to Buncrana Road in the suburbs of the city. The College has a student population of over 1,500, making it one of the largest Catholic Boys' Schools in Europe. Colloquially, the school’s name is often shortened to "The College".
St Columb's was initially intended to be a diocesan seminary, educating young men mainly, though not exclusively, for the priesthood. The establishment of such a seminary was an obligation imposed by the Council of Trent (1545–63). Ireland's political volatility and the suppression of Catholicism and Presbyterianism, particularly after the Williamite Wars, resulted in the delay of establishing any diocesan seminaries in Ireland for centuries. St Columb's college itself was preceded by several failed attempts to create such an institution in Derry. Repeated but sporadic efforts were made to maintain a seminary for almost a century; at Clady, near Strabane, in the late eighteenth century, at Ferguson's Lane in Derry in the early nineteenth century and at Pump Street (first reference to St Columb's College as such) in the city from 1841 to 1864.