Holt was born into a family of New York City actors, his mother was an actress and singer, and his father a Tony Award winning actor and producer. He began school in Dublin, Ireland at the age of five before his parents moved back to NY. At 14 years old, his long road began when he ran away from home and took a Greyhound bus to Los Angeles to pursue his dream of becoming an actor. Destined to be a star but not a runaway, Holt's parents tracked him down and sent him back to Ireland to boarding school. Following high school, he went to France to continue his education. He learned French at the Sorbonne, studied art history at the Paris American Academy, and theater at L'Ecole Marceau and L'Ecole Jacques Lecoq. He spent a summer studying Shakespeare in Oxford. After Europe, he moved back to New York permanently to begin his acting career. Holt has worked with some of Hollywood's top directors including David Fincher, David O. Russell, Lawrence Kasdan, David Twohy, Brian De Palma, and William Friedkin, among others. He most recently appeared in the Warner Bros. feature The Losers. Other films include Men of Honor, Three Kings, Fight Club, Below and Vantage Point and many others. Among his television appearances are such notable shows as CSI Miami, Law & Order: Criminal Intent, Burn Notice, Criminal Minds and Heroes. An accomplished writer and producer, McCallany co-wrote a film, "Mother Justice" based on the extraordinary life of Doreen Giuliano, a Brooklyn mother who risked her life to free her son from prison. The film will air on Lifetime Network. He resides in New York City and Los Angeles and enjoys reading history. He has read every biography from Bob Denard to Swifty Lazar.