The potential series will focus on a former CIA agent (Jim Caviezel) who teams up with a mysterious billionaire (Michael Emerson) to fight crime in New York City.
Deadline reports that Chapman will play an NYPD homicide detective who assists the pair with cases.
The actor previously appeared alongside Emerson in two episodes of Lost and has recently starred in Hawthorne, Cold Case and Leverage.
The Curious Case of Benjamin Button actress Taraji P. Henson will also appear in the Person of Interest pilot as another detective named Carter.
The project, written by The Dark Knight scribe Jonah Nolan, is under consideration for CBS's 2011-12 television season.