Longwick
Longwick is a village northwest of Princes Risborough, Buckinghamshire, England, on the A4129 road.
File:Roman gold polygonal finger-ring.jpg|thumb|left|A Roman gold finger ring, dated to CE and found in Longwick-cum-Ilmer in 2019
The toponym is from the Old English for "long farm".
With Ilmer, Owlswick, Meadle and Horsenden, it forms the civil parish of Longwick-cum-Ilmer which was created in 1934. In 1951 its population was 786, since when it has increased significantly to 1,267 in 2001.
Longwick was the location for the Sunrise/Back to the Future Acid House party on 12 August 1989.