The Treffry Tramways were a group of mineral tramways in Cornwall in the United Kingdom, constructed by Joseph Treffry (1782–1850), a local land owner and entrepreneur. They were constructed to give transport facilities to several mines and pits producing non-ferrous metal, granite and china clay in the area between the Luxulyan Valley and Newquay, and were horse-operated, with the use of water and steam power on inclines, and at first operated in conjunction with the Par Canal and Par Docks, also constructed by Treffry. One of the routes crossed the Luxulyan Valley on a large viaduct, the largest in Cornwall when it was built.
The tramways were opened in stages from 1835 to 1870. They provided a dramatic improvement in mineral transport, but they were technically obsolescent, and they were taken over in 1874 by the Cornwall Minerals Railway, a cash-rich company which invested heavily in improving railway transport in the area, making the lines suitable for locomotive operation and extending them.
The original sections were laid without the need for an act of Parliament, as a private venture, and the name of the lines is not defined; some writers refer to them as Treffry's Railway and other variants of the title. Tramway means a lightly constructed railway which is not generally fenced off. This is the essential character of a tramway, including street-running passenger lines in urban areas.
Today sections of the tramway route are still in use by passenger trains operating as the Atlantic Coast Line between Par and Newquay.