* ActorAllusion: Frank's mention of being a Marine with service in Vietnam. During ''Series/MagnumPI's'' run, Tom Selleck often wore a cap with the legend "VMO-2", which was a Marine Forward Air Control squadron out of Da Nang.
* TheDanza: Abigail Hawk plays ''Abigail'' Baker.
* DirectedByCastMember: Donnie Wahlberg (Det. Danny Reagan) directed "Manhattan Queens".
* TheOtherDarrin: Nicky was played by a different actress in the original pilot.
* PlayingGertrude: Tom Selleck is only 5 years younger than Len Cariou, who plays his father.
** Jack and Sean Reagan, Danny's two boys are played by real-life brothers Tony and Andrew Terraciano.
** In "Drawing Dead," Aida Turturro plays the shopkeeper questioned in an officer-involved shooting. She is a real-life cousin of Nicholas Turturro, who plays Sergeant Renzulli.
** Jennifer Esposito has coeliac disease and due to the condition, could no longer keep up with the grueling filming schedule required for her character. While the show writers were willing to work around it, [[http://www.hollywoodreporter.com/live-feed/jennifer-esposito-leaves-blue-bloods-381475 CBS were not]] and told the show to write her out, a decision she was ''not happy'' with.
** "Quid Pro Quo" was shot shortly after Hurricane Sandy hit New York City. The episode has Danny pay a visit at one point to a detective friend of his in the Rockaways, the part of the city hardest hit by Sandy. The shots of course being done on location in the Rockaways.
** Any episode with Reverend Potter in it highlights the levels of distrust between the police and the black communities, and some of them were produced around the same time that the "Black Lives Matter" movement - started in the wake of the deaths of Michael Brown and Eric Garner - took off.
** Some elements of "Forgive and Forget" and its lead-in "Custody Battle", specifically an officer using an unauthorized chokehold on a suspect that led to the suspect's death, invoke the controversy against the NYPD for the death of Eric Garner, himself the victim of an unauthorized chokehold.
** "Loss of Faith" has the NYPD dealing with the possibility of retaliation from a rogue ex-cop who was terminated from their ranks. The story does seem to have parallels to the case of Christopher Dorner, who went on a shooting rampage against the Los Angeles Police Department after he thought he was wrongly terminated.
* TheWikiRule: [[http://bluebloodstv.wikia.com/wiki/Blue_Bloods_Wiki Blue Bloods Wiki.]]
* YouMightRememberMeFrom: Creator/TomSelleck's role as Police Commissioner Frank Reagan is his first major role in quite a while, apart from a string of TV movies based on the ''Literature/JesseStone'' book series. He mentioned in an interview on ''Series/TheTalk'' that he took the job partly because the script made him cry.