The Thornton boat ramp sits on the western side of the Rangitāiki River estuary, near the river's mouth at Thornton Harbour, approximately 12 kilometres west-northwest of the Whakatāne River entrance.

The harbour entrance is characteristically narrow, flanked by a sandspit on the western side and a rock rip-rap training wall to the east, opening into a wide estuary upstream.

Facilities managed by the Whakatāne District Council include a double-width boat ramp, a timber wharf and jetty area, a dedicated waka ama launching ramp with associated storage, and car and trailer parking. The site is accessed via Thornton Beach Road.