The singer will play a college graduate named Wes who is involved in a car crash. Wes befriends George Eads's investigator Nick and the pair work together to figure out what happened, according to fan site The CSI Files.
Elizabeth Shue will make her debut as a series regular in the same episode, replacing Marg Helgenberger. The episode is scheduled to air February 15.
In February, McCartney landed a role in the Fox pilot Locke & Key. The network ultimately passed on the series.
McCartney previously appeared on All My Children, Greek and Summerland.