St. George’s was founded in 1792 at the instigation of the Rev. John Stuart, to serve the needs of the loyal Mohawk and United Empire Loyalists who had come north after 1783. Stuart, himself, had been Chaplain to the 2nd Battalion, King’s Royal Regiment and had arrived in 1785. He originally held services on the British Army barracks, in both English and Mohawk, and his Mohawk prayer book is still preserved in the Cathedral. The Church was named St. George’s as a token of loyalty to King George III. It was on the steps of the church that Gov. John Graves Simcoe proclaimed the Province of Upper Canada, on July 8th, 1792. In 1822, in order to keep up with the Catholics and Presbyterians, the Anglicans built a new, stone church, south of the original, with funds partly contributed by King George IV.

In 1862, the Diocese of Toronto was divided, and St. George’s became the Cathedral Church of the Diocese of Ontario. In keeping with its new status, the church was enlarged with the addition of transepts, a dome and a Lady Chapel. It was said to be based on St. Peter’s in Rome, or, perhaps more likely, St. Paul’s in London, which is the only Anglican Cathedral in England with a dome. The church was badly damaged by fire in 1899, but was rebuilt in the same form, with the later addition of interior lighting.

The Cathedral has stunning architecture, excellent acoustics and the largest organ in the region. It is, firstly, a centre of worship, but also for many musical and cultural events.