Smiths Falls (2006 population 8,777) is a town in Eastern Ontario, Canada. It is in the census division for Lanark County, but is considered a separated town and does not participate in county government. The Rideau Canal waterway locks in three locations in the town with four separate locks and a combined lift of over fifty feet.

The city is named for Thomas Smyth, a United Empire Loyalist who in 1786 was granted 400 acres (1.6 km2) in what is present-day Smiths Falls. The Heritage House Museum (c. 1862) also known as the Ward House, is on the Canadian Register of Historic Places.

Building of the Rideau Canal
At the time of construction of the Rideau Canal a small settlement had been established around a mill operated by Abel Russell Ward, who had bought Smyth’s land. Colonel By ordered the removal of Ward’s mill to make way for the canal. He settled with Ward for £1,500, one of the largest claims made by mill owners on the canal.

The disruption of industry caused by the building of the canal was only temporary, and Smiths Falls grew rapidly following construction. An article in Smith’s Gazetteer in 1846 described the town as a "flourishing little village pleasantly situated on the Rideau River and on the Canal, fourteen miles (21 km) from Perth. It contains about 700 inhabitants. There are fifty dwellings, two grist mills (one with four run of stones), two sawmills, one carding and fulling mill, seven stores, six groceries, one axe factory, six blacksmiths, two wheelwrights, one cabinet maker, one chair-maker, three carpenters, one gunsmith, eleven shoemakers, seven tailors, one tinsmith and two taverns."

A 36-foot (11 m) drop in less than a quarter of a mile posed an obstacle to navigation at Smiths Falls. A natural depression to the south of the river was used to create a flight of three locks, known as Combined Lockstation today. The natural course of the river was dammed to create a basin upstream of the locks. At the upper end of the basin a fourth (detached) lock was constructed.

Entry of the railways
In the 1850s the major railway companies were looking to build main trunk lines linking Toronto, Kingston and Montreal. The two major companies at the time, the Brockville & Ottawa and the Grand Trunk, were competing for the easiest routes to lay track. For a number of geographical reasons, and also due to the proximity of the Rideau Canal, the town of Smiths Falls became a major focal point for both railways. Both the Canadian Pacific and the Canadian Northern (later Canadian National) established stations in the town, however, with the creation of VIA Rail, the CN station was abandoned and all passenger traffic routed though the CPR station. The CN station has been renovated and is now home to the Smiths Falls Railway Museum of Eastern Ontario.