Omar Shafik Hammami (عمر شفيق همّامي, Umar Shafīq Hammāmī; 6 May 1984 – 12 September 2013), also known by the pseudonym Abu Mansoor al-Amriki (أبو منصور الأمريكي, Abū Manṣūr al-Amrīkī), was an American citizen who was a member and leader in the Somali Islamist militant group al-Shabaab. A federal warrant for his arrest was issued in 2007. In November 2012, the FBI added Hammami to its Most Wanted Terrorists list.
Omar was raised in a Christian household with an American Protestant mother and a Syrian-born Muslim father. Hammami began to identify as Muslim in high school, after traveling to Syria and meeting his Muslim relatives, and proceeded to drop out of college. After moving to Toronto, Ontario, Canada, and marrying a Somali-Canadian woman in 2004, he traveled with her to Egypt in 2005. He then abandoned his wife and infant daughter to join Al-Shabaab in Somalia in late 2006. They divorced, and by 2009 he had married a Somali woman and had another daughter.
Hammami served as a commander, propagandist, and recruiter. He was rumored to have been killed in March and July 2011 but later appeared again in videos. In December 2012, Al-Shabaab posted a rebuke online of what it called his "narcissistic pursuit of fame."
Hammami was killed by al-Shabaab militants on 12 September 2013.
Hammami was born to Shafik Hammami and Debra Hadley and grew up in Daphne, Alabama, with an older sister Dena. Hammami's father, Shafik, a Syrian Muslim, grew up in Damascus, Syria and moved to Alabama for college, later becoming a civil engineer. His mother, Hadley, is of Irish descent and was a former schoolteacher. The children were initially raised as Southern Baptist but also practiced Muslim culture at home. Finding her father too restrictive, Dena left the home at 16 and went to live with friends.
Hammami was president of his sophomore class at Daphne High School and was in the Advanced Placement program. Following his father's return to Islam, Hammami began to explore the religion.