The Algonquin Radio Observatory (ARO) is a radio observatory located in Algonquin Provincial Park in Ontario, Canada. It opened in 1959 in order to host a number of the National Research Council of Canada's (NRC) ongoing experiments in a more radio-quiet location than Ottawa.

Algonquin Provincial Park is an Ontario provincial park located between Georgian Bay and the Ottawa River, mostly within the Unorganized South Part of Nipissing District. Established in 1893, it is the oldest provincial park in Canada. Additions since its creation have increased the park to its current size of about 7,653 km2 (2,955 sq mi). The park is contiguous with several smaller, administratively separate provincial parks that protect important rivers in the area, resulting in a larger total protected area.