One of the most prolific architects in 19th-century Ontario, Langley was born in Toronto. In 1862, following his apprenticeship as an architect, he formed a partnership with Thomas Gundry. Langley undertook commissions for residential, commercial and public structures, but soon began to specialize in the design of ecclesiastical buildings. Working with the firm known initially as Langley, Langley and Burke from 1872 until his retirement, he developed an extensive practice, fashioning some 70 churches throughout the province and altering or enlarging many more. St. George's Anglican Church, completed in 1873, is representative of his masterly High Victorian Gothic designs. Well regarded by his peers, Langley figured prominently in the development of the architectural profession in Ontario, training many architects who later gained renown.