Raymond "Red" Reddington is a former government agent, presumed to be a member of the United States Navy; and number 4 on the FBI's Most Wanted List. A U.S. Naval Academy graduate, he was being groomed for Admiral when something happened on his way home for the Christmas holidays.

He is known for brokering deals between criminals, and is called "The Concierge of Crime". Red surrenders to the FBI and provides information on a roster of criminals that he refers to as "the Blacklist": dangerous criminals who are so careful that the FBI has not detected their existence.

His ethics are somewhat murky, and he espouses the use of some crimes (such as murder, torture, and extortion) in the service of "the greater good". He uses his arrangement with the FBI to pursue his own secret agenda. He has an unexplained interest in Elizabeth Keen, and knows personal secrets about her that she has never made public. It is implied several times that Reddington may be Keen's biological father. No proof of this is ever shown, and Red himself denies it when directly confronted by Liz, although he does claim that he knew her father well.