- "I know you might not feel the same way, but you will always be a son to me."
- —Roy Stewart to John Diggle[src]
Roy Stewart is a general in the U.S. Marine Corps and Defense Intelligence Agency, and former lieutenant in the Corps. He is the husband of an unnamed woman, the step-father of John Diggle and the late Andy Diggle, and the step-grandfather of A.J. Diggle and John Diggle, Jr. (Sara Diggle in the pre-Flashpoint timeline). Stewart is also a supporter of Oliver Queen/Green Arrow.
As a lieutenant in the U.S. Marine Corps, Stewart ran an op in Vlatava, during which an unnamed soldier and a number of others were killed. Six months later, he began visiting the unnamed soldier's widow, before eventually marrying her.
Stewart was briefly appointed as head of DARPA, he also served as a commander during a conflict in Kahndaq, for which he was twice-commended. Following this, he was appointed commandant of the Marine Corps, and later chairman of the Joint Chiefs of Staff.
Stewart eventually rose to the rank of general, he was visited by his step-son, John Diggle, and Oliver Queen, who hoped for help on a case regarding the Ninth Circle, but he was unable to, however, he sent men to help when the Ninth Circle attacked Smoak Technologies. Stewart was subsequently taken to the Arrowcave, where he explained that his people had been tracking the Ninth Circle's activities, he received a call, informing him of a single undercover agent, Julian Sison, who was unaccounted for, and so they mounted a search for him. John and the general were ambushed by Dante, who tranced and kidnapped them, Dante tortured them until Stewart gave up codes to Cygnus X-1, before they were able to escape, Team Arrow proceeded to track the Ninth Circle through their use of the Archer program; Stewart helped oversee the operation, though unsuccessful in stopping them from stealing Cygnus X-1, they destroyed Archer. Following the mission, Stewart and John said their goodbyes, making amends.
John Diggle describes Stewart as "a real hard-ass". He claims to always have time for his family. He let John believe his biological father was a war hero. Felicity Smoak described him as "a real bona fide American hero".
- High-level intellect/Military training/Master tactician/Leader: As a lieutenant, later 4-star general of the United States Army, Stewart is a highly intelligent individual, an excellent tactician and leader; according to Oliver Queen he is at the top of the chain of command. Originally, Stewart was a lieutenant and Mr. Diggle's commanding officer on a covert military operation to quell an insurgency in Vlatava. While the operation failed, Stewart was responsible for getting the remaining Marines out alive. Since then, he became a three-time decorated commander of the 1st Recon Battalion during the Khandaq Conflict, after which he was appointed commandant of the United States Marine Corps, then chairman of the Joint Chiefs of Staff. For a stint of time, Stewart was appointed head of DARPA. He cleverly used Dante's taser baton to recharge John Diggle's Spartan helmet, which allowed Felicity Smoak to track them to a warehouse in the Meatpacking District of Star City.
- Expert hand-to-hand combatant: As a lieutenant, later general of the United States Army, Stewart is an extremely skilled hand-to-hand combatant, having gone through the same training that all United States soldiers do.
- Master survivor: Stewart learned extensive survival skills as a recon Marine, which he had John and Andy Diggle run through (namely how long they could be out in the cold trying to find their way out of the woods without a compass). Among Stewart's skills included how with enough pressure applied at a steady pace, a shoelace can saw through plastic.
- Stewart's Marine Corps serial number is 498003145.
Behind the scenes
- In the DC comics, Roy Stewart was the grandfather of John Stewart/Green Lantern.