The Cathedral of St. Alban the Martyr is an unfinished Anglican church in Toronto, Ontario, which serves as the school chapel of Royal St. George's College.

Completed in 1891, what stands today is only two-thirds of the planned Gothic Revival church designed by Richard C. Windeyer, Sr. to serve as the cathedral of the Anglican Diocese of Toronto.

[2] Even before ground was broken, the Legislative Assembly of Ontario passed a special act designating St. Alban's as the cathedral of the diocese.

[2][6] Sir Henry Mill Pellatt, of Casa Loma, and Edward Marion Chadwick were major benefactors of the project.

[2] In 1936, Derwyn Owen, 5th Bishop of Toronto and Primate of All Canada, formally cancelled all plans to ever complete the cathedral and returned the diocesan seat to St. James's.

[8] Since 1964, St. Alban's has been the school chapel of Royal St. George's College (RSGC) which is built on the foundation of the cathedral's unfinished nave.

The school was founded in 1961 as St. George's College by a group of Anglican clergy and laity, including composer Healey Willan, choirmaster of the Church of St. Mary Magdalene, who had the vision of establishing a permanent home for boys' choral music in Canada.

At the suggestion of Frederick Wilkinson, 7th Bishop of Toronto, the newly established college began renting St. Alban's property.

Though the arrangement was originally intended to be temporary as the school looked for property in the country, in 1970–72, RSGC built their classrooms, offices and gymnasium in the Brutalist style on the foundation of the unfinished nave.

[2] Richard Cunningham Windeyer, Sr.'s original design was a Norman inspired Gothic Revival cathedral with a cruciform floorplan complete with a 135-foot tower.