Tyun (Armenian letter) should not be confused with S.
| Tyun | |
| Letter: | Տ տ |
| Imagealt: | Shghagir variant of Tyun |
| Script: | Armenian script |
| Type: | Alphabet |
| Typedesc: | ic |
| Language: | Armenian language |
| Phonemes: | [{{IPAlink|t}}] [{{IPAlink|d}}] |
| Unicode: | U+054F, U+057F |
| Alphanumber: | 31 |
| Number: | 4000 |
| Usageperiod: | 405 to present |
Tyun, Tyown, or Tiwn (majuscule: Տ; minuscule: տ; Armenian: տյուն) is the thirty-first letter of the Armenian alphabet. It has a numerical value of 4000.[1] The uppercase is similar to an uppercase S, whilst the lowercase is like a ligature of lowercase U and N.