Locally everyone calls it 'the Jes' - the Jesuits' school. Students are organised in year-groups divided into four classes named for figures from Jesuit history: Gaeilge (the Irish-language stream), Xavier (after Francis Xavier the missionary), Loyola (after the founder Ignatius), and Collins (after Dominic Collins, the Irish Jesuit lay brother executed in 1602). In Transition Year the classes reshuffle into Brebeuf, Gonzaga, Ricci, and Claver - Jean de Brebeuf the Jesuit martyr among the Huron, Aloysius Gonzaga the seventeenth-century saint, Matteo Ricci the missionary to Ming China, and Peter Claver who ministered to enslaved Africans arriving at Cartagena. Transition Year is compulsory at Iognáid, where in many Irish schools it is optional. The four-year-group system is the kind of organisational quirk that Jesuit schools produce naturally - a structure expressing a theology.

The 1645 foundation was an act of defiance during the Confederate Wars, the brief period when Catholic Ireland controlled most of the country. Classroom Latin, with only Irish-speaking Jesuits sent on what was called the Irish Mission. The school relocated multiple times across the centuries - through suppression, restoration, suppression again, restoration again. The current Sea Road campus dates from the nineteenth century, with major expansion in 1982. The O'Reilly Building added a new science block; the Andrews Building refurbished classrooms; libraries, art rooms, computer facilities and an indoor sports area followed. In 1984 the school went fully co-educational - the first secondary school in Galway city to do so. The shift was practical as well as ideological. The Jesuits had run boys' schools for centuries; opening to girls reflected both a changing church and a changing Ireland.

Coláiste Iognáid Rowing Club - CIRC, founded in 1922 - produces Olympic rowers with a regularity that punches well above the school's size. Cormac Folan of Bearna rowed in the bow seat of Ireland's heavyweight men's four at the 2008 Beijing Olympics. In 2009 Zoe Mannion and Aifric Keogh, rowing for Ireland at the European Junior Championships in Vichy, won silver in the women's pairs. Aifric Keogh went on to win bronze in the women's coxless four at the Tokyo Olympics in 2021 - Ireland's first Olympic rowing medal for a women's crew. The Jes also produces national hockey teams (All-Ireland winners in 2009), Connacht rugby Schools Senior Cup winners (a record-breaking eight times in the new millennium - 2002, 2005, 2006, 2008, 2009, 2011, 2016, 2017), and a debating record that includes multiple wins of the West of Ireland Debating Competition and the National Junior Mace.

The alumni list is striking for its range. Eric Elwood and Claire Molloy played senior rugby for Ireland. Aifric Keogh rowed at Tokyo. The journalist Sean Duignan was political aide and writer; Sean O'Rourke became RTE's most listened-to morning presenter; Padraic O Raghallaigh was the first Ceannaire (head) of RTE Raidio na Gaeltachta when the Irish-language radio station opened in 1972. The cardiac surgeon Eoin O'Malley. The legal scholar Paul O'Higgins. Father Peter Yorke - an Irish-American Jesuit-trained priest who became a major labour activist in early-twentieth-century San Francisco. The novelists, the writers, the public-affairs people. And then, awkwardly: William Joyce, who broadcast Nazi propaganda from Berlin during the Second World War as 'Lord Haw-Haw' and was hanged in Wandsworth Prison in 1946. The school does not pretend he did not exist. His name is part of an honest reckoning with what an institution produces over four hundred years.

The school's bilingualism is structural. One class per year-group works through Irish to Junior Certificate level. The other classes have Irish as one subject among many, but the cultural framing - Gaeilge first in the list of class names, Irish-language drama as part of school life, the annual Feile Scoil Dramaiochta competition - keeps the language alive in a way many Irish schools do not. The Jesuit charism is the older skeleton: education as a serious enterprise, the formation of conscience as well as of intellect, the principle of magis - 'more', the obligation to take the harder road when it is the right one. The school stages a musical every year. The debate teams reach the international finals. The mountaineering club organises trips into Connemara. Six hundred kids, no uniform, the Atlantic two streets away. The Jesuits have been doing it since 1645 and show no obvious sign of stopping.