In 1998, Settle made his big screen debut as a college student friend of Jennifer Love Hewitt's stalked Julie who accompanies her on a resort vacation turned deadly in "I Still Know What You Did Last Summer". The actor reached a large audience with his portrayal of Will, a young man with a deadly secret, and earned himself a loyal fan base. He followed up with more TV work, playing a young Bugsy Siegel (Eric Roberts portraying the gangster later in life) in David Mamet's fact-based portrait of early organized crime figure "Lansky" (1999) and rounded out that year with a starring turn in the fact-based TV-movie "Crime in Connecticut: The Return of Alex Kelly" (CBS), portraying the titular rapist from a wealthy family who dodged authorities for eight years living a privileged life in European ski lodges. Settle managed to make the character appropriately detestable yet capable of believably projecting a charming facade, and the high-profile nature of the case and resulting interest surrounding the telepic garnered him increased visibility.
In 2000, Settle returned to the big screen with three notable film roles, beginning with a featured turn in the ensemble of the suspenseful World War II action drama "U-571", playing Ensign Larson, one of a troop of Americans on a mission to learn German war secrets who end up as stowaways on an enemy U-boat. Later that year he starred as Matt Curtis, a dashing tennis pro and member of "The In Crowd", an elite group that a mysterious newcomer will do anything to join. Settle also had a co-starring role alongside Gretchen Mol in "Stalk", an independent dark comedy about an obsessive love relationship.