John M. Lyle, Irish-Canadian architect and educator, designed the Royal Alexandra Theatre (d. 1945)

John MacIntosh Lyle (13 November 1872 – 20 December 1945) was an Irish-Canadian architect, designer, urban planner, and teacher active in the late 19th century and into the first half of the 20th century. He was a leading Canadian architect in the Beaux Arts style and was involved in the City Beautiful movement in several Canadian cities. In the 1920s, he worked to develop his vision of a uniquely Canadian style of architecture.