Mark Pellegrino portrays Jacob in "The Incident, Part 1".
- The day after "The Incident, Part 1" aired, appeared on CSI: Crime Scene Investigation alongside Lost co-stars Cynthia Watros and Marc Vann.
- Appeared in the series "Prison Break" as Vicon (2008)
- Appeared in the 2006 film "Caffeine" alongside Lost co-stars Marsha Thomason and Sonya Walger.
- Appeared in the 2004 film "Twisted" alongside Lost co-star Titus Welliver.
- Appeared in the 2001 film "Mulholland Dr." alongside Lost co-star Patrick Fischler
- Appeared in the 2001 tv series "The Beast" alongside Lost co-stars Elizabeth Mitchell and Naveen Andrews
- Appeared in the 1998 film "The Big Lebowski"
- Appeared in the pilot episode "Genesis" (1996) of the series "Nash Bridges" written by (episode) and created by (series) Lost writer Carlton Cuse. The show stared Cheech Marin.
- Mark is an acting teacher in Los Angeles at the same acting school where Nestor Carbonell, the actor who plays Richard Alpert, is a student.