Shimr Ibn Thil-Jawshan Ibn Rabiah Al Kilabi (Arabic: شمر بن ذي الجوشن بن ربيعة الكلالي) was the commander of the Ummayad army during the Battle of Karbala, in southern Iraq that occurred in the year 680 AD. He was from the same tribe, Bani Kalb (Arabic: بني كلب) as Abbas ibn Ali's mother.
In battle, he was responsible for beheading Husayn ibn Ali, the grandson of the prophet Muhammad. He was also instrumental in pillaging the camp of Husayn after raising his head on a post to declare his victory
Shimr was eventually killed by Al-Mukhtar's troops who wished to take revenge upon the killers of Husayn and the rest of the members of the Prophet's family.