| Jan Seyum | |
| Succession: | King of Zagwe dynasty |
| Reign: | 1056 A.D.-Late 11th Century |
| Predecessor: | Tatadim |
| Successor: | Germa Seyum |
| Dynasty: | Zagwe dynasty |
| Father: | Mara Takla Haymanot |
| Mother: | Masoba Warq |
| Religion: | Ethiopian Orthodox Church |
Jan Seyum (Geez: ጃን ስዩም) was King of Zagwe dynasty. Taddesse Tamrat states that he was a son of Mara Takla Haymanot, a younger brother of King Tatadim, and the father of Yemrehana Krestos.[1] His name does not appear in the longer king lists.