This is a list of secondary highways in Nipissing District, many of which serve as logging roads or provide access to Algonquin Park and sparsely populated areas in the Nipissing District of northeastern Ontario.
Secondary Highway 531, commonly referred to as Highway 531, is a provincially maintained secondary highway in the Canadian province of Ontario. It connects Highway 17 east of North Bay with the community of Bonfield. The 3.5-kilometre (2.2 mi) route was established in 1956, and has remained the same since then. It passes through a forested area and has several private residences located along its length. Aside from Maple Road, its southern terminus, and Highway 17, its northern terminus, Highway 531 encounters no roads along its length.
Secondary Highway 539, commonly referred to as Highway 539, is a secondary highway in the Canadian province of Ontario, located within the Sudbury and Nipissing Districts. Commencing at a junction with Highway 17 in the community of Warren, the highway extends northeasterly for 23.4 kilometres (14.5 mi) to the community of River Valley, and thence southeasterly for 13.6 kilometres (8.5 mi) to a junction with Highway 64 in Field.
A spur route, Highway 539A, extends northwesterly from Highway 539 at River Valley.
^ ab"Ontario Secondary Roads Now Designated 500, 600". Vol. 112, no. 33, 119. The Globe and Mail. February 4, 1956. p. 4. Two new Ontario road numbers appear on the province's 1956 official road map which will be ready for distribution next week. The new numbers are the 500 and 600 series and designate hundreds of miles of secondary roads which are wholly maintained by the Highways Department. More than 100 secondary roads will have their own numbers and signs this year. All of these secondary roads were taken into the province's main highways system because they form important connecting links with the King's Highways