Pellegrino has appeared in episodes of The Beast, NYPD Blue, Without a Trace, Dexter, Grimm, Prison Break, CSI: Crime Scene Investigation, The Mentalist, Burn Notice, and The Number 23.
He is best known for his role in the Americanized version of the UK supernatural drama Being Human as the leader of the Boston vampire group Bishop. Another major role is his portrayal of Jacob in Lost.
One of his most recent television roles was Dr. Jedikiah Price, on the The Tomorrow People, which was ultimately canceled. He later appeared on Quantico as Clayton Haas.
He has also starred in other roles alongside fellow Supernatural cast members, such as Moving Alan with Misha Collins and The Closer with Curtis Armstrong. He has also done minor roles with Mark Sheppard and Kurt Fuller.
Mark is married to Tracy Aziz and stepfather of her daughter Tess. Mark is an atheist.
- According to Supernatural creator Eric Kripke, Mark did not require auditioning for the role of Lucifer.
- Previously, Mark had auditioned for the role of Castiel, which was given to Misha Collins.
- Previously, Mark did not watch Supernatural or any of his other television roles, instead he let his wife Tracy review them. Recently, Mark began watching them and occasionally tweeted his reactions.
- At Vancon 2012, Richard Speight Jr. had gotten Mark drunk, which led to him dancing rather seductively in front of the fans. Richard quickly regretted this decision.
- Although known for his many roles as antagonists, Mark is a staunch believer that his characters are not "bad guys". This is especially the case with Lucifer.
- Season 5
- Season 7
- Season 11
- Season 12