Ypsilon (Υ or υ) is another name for upsilon, the 20th letter of the Greek alphabet.
The spelling Ypsilon may also refer to:
Lancia Ypsilon, a car Ypsilon (bridge), a bridge in Norway Ypsilon, Kyrgia, Doxato, Drama, Greece; a village Ypsilon Mountain, a mountain in Colorado, USA Ypsilon (Scheme implementation), a software implementation
See also Ipsilon (disambiguation) Upsilon (disambiguation)