Umar ibn Sa'd

ʿUmar ibn Saʿd ibn Abi Waqqas (عمر بن سعد; died 686) was a son of prophet Muhammad's companion, Sa'd ibn Abi Waqqas. He was born in Medina and later moved to Kufa, which was founded by his father and stayed there until his death.

He took orders from Ubaydullah ibn Ziyad. He was one of the leaders of the troops who killed Husayn ibn Ali in the Battle of Karbala in 680, the first major battle of the Second Islamic Civil War (Second Fitna).

His wife was the sister to Mukhtar al-Thaqafi, who ruled Iraq from 685 to 687, during the Second Fitna. He had five sons, of which Hafs ibn Umar ibn Sa'd ibn Abi Waqqas was present at the battle of Karbala.

Umar ibn Sa'd was killed by Abu Amra Kaysan, on the orders of Mukhtar al-Thaqafi, for his involvement in the Battle of Karbala.