Sin-shumu-lishir (or Sin-shum-lishir), was a usurper king of a part of the Assyrian empire in 626. Little is know about this king due to the lack of sources of his time.
Sin-shumu-lishir first shows up in Assyrian sources as the general of Ashur-etil-ilani. It seems that he later tried to take kingship for himself. He is credited of having reigned one year by the Uruk king list, preceding Sin-shar-ishkun. His first year was attested in texts from Babylonian cities Babel, Nippur, and Ru'a. Because we only know about his first year it is not lilololkely that his reign lasted much longer. Sin-shumu-lishir never controlled all of the Assyrian empire and most likely only a part of Babylonia. His short reign must have taken place in 626 because before that year Kandlolololalanu reigned over his attested cities and after that Nabopolassar and Sinsharishkun.