A puzzled Art keeps his eye on Simon at his second visit to the Lynch house - June 8, 1998
|Full Name||Arthur David Jeffries III|
|Born||October 17, 1955 (Age 43)|
|Status||FBI special agent since 1984|
|Parents|| Art Jeffries, Jr. (deceased)|
|First appearance||Mercury Rising|
|Portrayed by||Bruce Willis|
- "Hey! Would you forget about South Dakota? Forget about who's right and who's wrong, this is one of the best undercover guys we've ever had."
- —Tommy Jordan at debriefing for Jeffries, Kluczynski Federal Building. June 5, 1998.
Arthur David Jeffries III, better known to his friends as simply Art, is the son of Art, Jr. and Amanda Jeffries, one of the main protagonists of Mercury Rising and The Series, and current foster father of Simon Lynch. He is an FBI special agent, and after a botched undercover job infiltrating radical Edgar Halstrom's militia group in the town bank of Sturgis, South Dakota and striking operational Supervisor & Richmond, Virgina A-SAC John Hartley, Art was removed from undercover duty and placed on 'rookie' assignments by his boss, Chicago SAC Joe Lomax. Art first met Simon Lynch on June 7 - two days after Lomax had removed him from undercover duty - when he discovered the boy hiding in a crawl space in his closet after Peter Burrell had murdered the boy's parents, Martin and Jenny Lynch in their home at 2144 West 23rd Street in Chicago's Lower West Side. From this point on, Art began to slowly develop a repertoire with Simon, though it took the boy nearly being killed at various times between June 7 and 12th for him to finally accept Art as a friend and person of his trust. Art was also responsible for the death of Lt. Colonel Nicholas Kudrow, Burrell's boss and commander of the NSA department known as Division on June 12 at the IBM Building's GEX Skydeck. Beginning on February 7, 1999, after a shootout between an FBI SWAT team and a strike team of unknown origin, Art was again thrown to Simon's defense in the fight against their new adversaries, Colonel Robert Donaldson and Major James Striker of the NSA's black-ops Zero Section.
- Art is portrayed by Bruce Willis, who was born March 19, 1955.
- In Simple Simon, Art's character was originally African American, at least 55 or 60 years old, had the last name of Jefferson, and a wife named Anne.