Co-starred as undocumented Syrian immigrant Tarek in the critically acclaimed 2008 independent film The Visitor, a drama nominated for a Screen Actors Guild Award and an Oscar, directed by Thomas McCarthy. Sleiman also had small roles in the 2006 film American Dreamz and the 2007 film AmericanEast.
In 2006 Sleiman portrayed an American soldier in Iraq on the NBC series ER, and that same year had a recurring role as an Arab billionaire in the CBS series "Company Town". He portrayed the terrorist suspect Heydar in three 2007 episodes of the FOX series 24, and appeared on both NCIS and Veronica Mars in 2007.
|2004||The Ski Trip||Tyson|
|2006||Company Town||Abby Faisal||TV movie|
|Fourth Estate||Short video|
|American Dreamz||Mujeheddin Captain|
|ER||Hodgkins||Episode "The Gallant Hero and The Tragic Victor"|
|2007||24||Heydar||3 episodes (season 6)|
|NCIS||Abdul Wahid||Episode "Grace Period"|
|Veronica Mars||Nasir Ben-Hafald||Episode "Un-American Graffiti"|
|Futbaal: The Price of Dreams||Ace|
|Assassin's Creed||Malik al-Sayf (voice)|
|AmericanEast||Slick Ali, the angry customer|
|2009||Nurse Jackie||Mohammed 'Mo-Mo' De La Cruz||12 episodes (main cast season 1)|
|2010-2011||The Promise||Omar Habash||Part 1, 2, 3, 4|
|Nikita||Kasim Tariq||Episodes "One Way" and "Covenant"|
|2011||Meet Jane||Agent Joseph Omari||TV movie|
|CSI: Miami||Marcel Largos||Episode "Mayday"|
|Dorfman In Love||Cookie|
|Assassin's Creed: Revelations||Suleiman I (voice)|
|2012||Highland Park||Ali Rasheed|
|2012||Covert Affairs||Khalid Ansari||5 episodes (Season 3)|
|2013||East of Broadway||Ali|
|2013||Blue Bloods||Damiri||Episode: "Drawing Dead"|
- Durling, Roger (May 1, 2008). "A Chat with Haaz Sleiman, Star of Tom McCarthy’s The Visitor". Santa Barbara Independent. Independent.com. Retrieved February 5, 2009.
- "Nurse Jackie Actor Bios: Haaz Sleiman". Sho.com. Retrieved June 16, 2009.
- "American East (2007) Cast Biographies: Haaz Sleiman". AmericanEastMovie.com (Internet Archive). Archived from the original on October 16, 2007. Retrieved October 16, 2007.
- "Nurse Jackie: Official Site". Sho.com. Retrieved March 3, 2009.
- Starr, Michael (June 30, 2008). "Nurse Edie: First Look at Sopranos Star's Dark, New Hospital Comedy". New York Post. NYPost.com. Retrieved March 8, 2009.
- Juergens, Brian (December 23, 2008). "Meet the gays of The United States of Tara and Nurse Jackie". AfterElton.com. Retrieved March 8, 2009.
- Ausiello, Michael (December 22, 2009). "Exclusive: 'Nurse Jackie' Drops Mo-Mo!".