Farrell had roles in television shows and films, including Ballykissangel and Falling for a Dancer in 1998 and 1999. He made his feature film debut in English actor Tim Roth's directorial debut The War Zone, a drama about an incident of child abuse, starring Ray Winstone and Tilda Swinton as parents of a girl Farrell's character (Nick) dates. Farrell also appeared in Ordinary Decent Criminal with Kevin Spacey and Linda Fiorentino, a film loosely based on the life of Martin Cahill. In 2000, Farrell was cast in the lead role of Private Roland Bozz in Tigerland, an under-released film directed by American Joel Schumacher. He reportedly got the part on the basis of his charm. Emanuel Levy of Variety said that Farrell "shines as the subversive yet basically decent lad whose cynicism may be the only sane reaction to a situation". Michael Holden of The Guardian wrote that Farrell was "too much the hero" to fit the classic rebel archetype properly, but he did not mind. Tigerland earned $139,500.