Wynn or wyn (; also spelled wen, win, ÿynn, ÿyn, ÿen, and ÿin), is a letter of the Old English alphabet, where it is used to represent the sound . It was a continued use of the Anglo-Frisian Futhorc runes. Futhorc was the native alphabet of Old English before the Latin alphabet was adopted, and it was a sibling alphabet to the Younger Futhark alphabet that Old Norse used. Both alphabets come from Elder Futhark.
While the earliest Old English texts represent this phoneme with the digraph , scribes soon revived the rune wynn from Old English's native alphabet, Anglo-Frisian Futhorc, for this purpose. It remained a standard letter throughout the Anglo-Saxon era, eventually falling out of use during the Middle English period, circa 1300. In Middle English texts, it was sometimes replaced with or with a ligature form of , until it was replaced with the modern letter .
The denotation of the rune is ", ", known from the Anglo-Saxon rune poems:
The following wynn and wynn-related characters are in Unicode: