The birth date listed on the Raymond Reddington wanted posters is the actual birth date of actor James Spader (February 7, 1960).
Bazzel Baz, who plays Red's chief of security Baz, is a veteran US marine and a former member of CIA's Special Operations Group. He is the founder of the Association for the Recovery of Children (ARC), which rescues abducted children. In 1991-2012, they had conducted 56 successful rescues.
Red's signature fedora came about as a result of a suggestion from series star James Spader.
Agent Ressler is loosely based on Robert K. Ressler, a former FBI agent and author, who played a significant role in the psychological profiling of violent offenders in the 1970s and is often credited with coining the English term "serial killer". He was also fundamental in the setting up of the ViCAP system . (Violent Criminal Apprehension Program )
Creator Jon Bokenkamp loosely based Raymond Reddington character on the real-life Boston mafia boss, James 'Whitey' Bulger. As explained at the 2013 Comic-Con panel, many news stories concerning Bulger's arrest and trial were prevalent at the time. Bokenkamp tossed around a few "what if?" scenarios and came up with the basic concept of the show, anchored by the nefarious "concierge of crime" we now know as Red. Although Spader came in very late to the concept (within approximately two weeks of the principal shooting of the pilot), he can be credited with largely contributing to the final "look" of Reddington: closely cropped hair, hat collection, Rx shades (for practicality - Spader really does need them to see), iconically tailored vest-tie-trousers-shirt ensemble, and the infamously expensive ($5,000?) all-weather navy blue coat. As for the acerbic humor & raconteur tendencies of Red? Spader claims these were already present in the pilot script, however one can't help but think that the writers expanded these qualities once they got to know Spader a bit better.
Many of The Blacklist actors also appear in Homeland (2011): e.g. Amir Arison played Prince Farid Bin Abbud in season 1, Diego Klattenhoff was Mike Faber in seasons 1-3, Omid Abtahi (Khan of S02E09) was Raqim Faisel in season 1, William Sadler (Sam of S01E08) was Michael Higgins in season 3, and Mark Ivanir (Ivan of S01E17) was Ivan Krupin in season 5.
Andrew McCarthy (who directed 6 episodes) appeared in "Pretty In Pink" and in "Less Than Zero" with James Spader (Ray Reddington).
Rachel Brosnahan (Lucy Brooks/Jolene Parker), Reed Birney (Tom Connolly), and Mozhan Marnò (Samar Navabi) were all part of the cast of House of Cards (2013), starring Kevin Spacey.
Prior to the episode "Cape May" the title of every episode was the name of a criminal on the blacklist.
Diego Klattenhoff who plays Agent Donald Ressler appeared as Team Leader on an episode of Stargate SG-1 in Stargate SG-1: Ex Deus Machina (2005), which was based on the movie Stargate Stargate (1994) that starred The Blacklist star James Spader.