Ottawa Electric Railway Company was a streetcar public transit system in the city of Ottawa, Canada, part of the electric railway streetcars that operated between 1891 and 1959. Ottawa once had tracks through downtown on Rideau Street, Sparks Street and others, and extended outside of the downtown core to provide services that helped form communities such as Westboro, Old Ottawa South and The Glebe. Prior to this, starting in 1866, public transportation was provided by Ottawa City Passenger Railway Company, a horse-drawn tram service. The O.E.R. was taken over by the Ottawa Transportation Commission in 1948, which was itself succeeded by OC Transpo in 1973.
Preceding the use of electric streetcars, Ottawa's first public transportation system was the operation of a horsecar system. Tramway service began in July 1870. under the Ottawa City Passenger Railway Company, which was incorporated on August 15, 1866.
The O.C.P.R. was financed largely by the estate of Thomas McKay (an early founder of Ottawa). In 1868, Thomas Reynolds bought control of the company intending to use it to transport lumber at night from the Chaudiere mills to McTaggart Street, the terminal of the St. Lawrence and Ottawa Railway. In 1871, Reynolds sold his streetcar company interest to Thomas Keifer.
The horse-drawn streetcars travelled back and forth from New Edinburgh to the Chaudière Bridge. The trams for passengers and freight had a line extending from Rideau Falls in New Edinburgh, to Sussex, Sparks, Wellington, Duke (in Lebreton Flats) and the Suspension Bridge. The service provided sleighs in the winter and had 273,000 passengers in its first year of operation. In 1891, it had four miles (6.4 km) of track, 25 horses and 15 employees.