The London Society of Architects (LSA) is a local society of the Ontario Association of Architects (OAA). It is a venue for dialogue, a support network for local professionals, and a vehicle for social interaction, continuing education and community outreach.

The London Society of Architects extends beyond the municipal border of the city of London to include the counties of Bruce, Huron, Perth, Middlesex, Oxford, Elgin and Haldimand-Norfolk.