Christopher Jon Castile (born June 15, 1980 in California) is an American actor. He was best known for his roles as Ted Newton in the movies Beethoven and Beethoven's 2nd, as well as playing Mark Foster on the long running sitcom Step by Step. He also voiced Eugene Horowitz in Hey Arnold!.

One of Castile's earliest television appearances was in a long-circulated segment of Totally For Kids, kid safety interstitials that aired on the Fox network's Saturday morning lineup in the early 1990s. The segment had Chris playing a young boy who was being followed by a group of kids (the main characters of the "safety patrol") because he had his named printed on his shirt, as a way to address the dangers of name display for strangers (or possible abductors) to see. The Totally For Kids segments also featured John Walsh.

Shortly after, Castile auditioned and became a part of the revamped cast of the Miller-Boyett sitcom Going Places in January 1991. The show never improved in the ratings with the new cast members, in a show that was already starring such talents as Alan Ruck and Heather Locklear, and was cancelled by ABC at the end of its only season. However, Castile and his fellow Going Places cast member Staci Keanan were approached by Miller-Boyett about a new family sitcom that was in development for the fall; both were promptly hired to play biological brother and sister on Step By Step, which they would for the next seven years.

The same year that Castile appeared in both Going Places and Step by Step, the film Beethoven was released, giving the young actor some movie exposure for a time. Following the success of the film, Castile was offered a major role in the independent film Remington Under the Bridge, an uncharacteristically dark drama about a homosexual relationship between two adolescent sociopaths in a Connecticut boarding school in the 1960's. Unexpected trouble with funding caused production on the film to be halted less than halfway through shooting, however.

Has a pilot's license.

Wrote his autobiography, "Being You is Most Definitely Cool."

Parents, Jon and Donna.

Has a younger sister, Bethany.

Loves playing golf.