A previous iteration of Highway49 existed between 1936 and 1961 from Kleinburg west to the York County boundary south of Bolton, which is today known as York Regional Road 49 (Nashville Road). The current Highway49 was created in 1965 as an internal designation for the proposed route connecting the newly-opened Highway 401 with the skyway over the Bay of Quinte.
A previous iteration of Highway49 existed from 1936 to 1961 along Kleinburg's western edge to the York County boundary south of Bolton, now designated as York Regional Road 49 (Nashville Road). The current Highway49 was created in 1965 as a proposed route linking the newly-built Highway 401 with the skyway spanning the Bay of Quinte.