The Brockville Railway Tunnel is Canada's first railway tunnel and is located beneath the city of Brockville, Ontario. The tunnel runs in a north/south direction from Water Street, for a distance of 527 m (1,730 ft). Construction on it began in September 1854 and was opened for rail traffic on 31 December 1860.

In the early1980s, the rails and ties were sold and removed and the Railway Tunnel was no longer used as it was built. In 1982, the tunnel was turned over to the City of Brockville by Marathon Realty, the real-estate wing of the Canadian Pacific Railway.

Then in 2016-17, the Railway Tunnel underwent a major interior rehabilitation to make it possible for citizens and visitors to travel safely on foot through it. The tunnel now features a modern LED coloured light system, which is programmed in various ways, along with a recorded music track playing as one walks through its length.