Scully can sing opera. He has an ex-wife and a dog, one of which is named Kelly. He has two children, who he says no longer speak to him. He is assumed to be currently in a relationship with Cindy Shatz.
In Thanksgiving, Scully attends Amy's Thanksgiving, and even he won't eat Amy's food, as it is so horrible.
In The Party, Scully reveals that he met his wife on the street, as she was leaving an orgy. He also sings opera for the party guests and Hitchcock, leading the guests to believe that they're in a relationship. One of the guests even asks if they get harassed for being an openly gay couple in the 99 who work together.
In The Apartment, it's revealed that in a year, they had made fourteen arrests between them. Captain Holt wasn't happy with that number, but Terry points out that it's 'six more than last year'. In comparison, Jake alone made seventy-eight arrests. Despite this, they're kept around.
During The Jimmy Jab Games, Scully is seen in the morning meeting with his flask. Jake uses Scully to invent the monster mouth bagel toss (throwing bagel pieces into Scully's mouth while he's napping). Scully does his opera singing 'Jimmy Jab' during the short opening ceremony, wearing a scarf and holding a hockey stick. During the first contest, eating month old Chinese food, Scully eats the most food, saying 'you know this is free, right?' He then quickly develops food poisoning and has to drop out of the competition, beating only Boyle.
At the beginning of Halloween II, Jake doesn't give him or Hitchcock code names in order to prevent confusing them. However, Scully was on Holt's team and dressed up as a bear with Hitchcock in order to separate him to Boyle as well as steal his wallet. Using his phone, he records Jake saying 'Captain Holt, you are an amazing detective slash genius'.
In The Mole, Lt. Andrew Miller from Internal Affairs arrives trying to find the unit's mole. He calls Scully up to talk to him. Scully stands up, with a napkin tucked into his jumper; it's covered in sauce, as well as it being around his mouth from the sandwich that he was eating at the time. Miller, being a germaphobe, decides to do the interview over the phone after taking one look at the messy Scully. He also announced to Holt that his dog has taken over his favorite chair.
In Captain Peralta, it is revealed that his parents left him at the Louvre in Paris when he was 9, and they didn't notice until they had returned to Queens. In the time he was there, he learned French. However, he doesn't appear to be very good.
In The Funeral, Holt is very impressed with Scully's fake crying. Scully reveals that he had received a text from his wife saying that she's leaving him.
In House Mouses, Hitchcock and Scully are put on a drug case by Jake so he can solve another case with an oboist. During their case, it turns into the biggest drug bust the Nine-Nine has ever had. Hitchcock and Scully's plan was to go undercover as Tex Dallas and Rino Vegas, mobsters with connections to the cowboy mafia who work for the Dallas Buyers Club, their plan was called "Operation Beans". The drug ring doesn't buy it, causing Terry and Jake to save them, this fails. Hitchcock and Scully then escape by using Hitchcock's chair abilities to roll up the stairs, tripping one of the guys that has them hostage, Scully then rips off the duct tape due to the amount of sweat he has and gives a gun to Terry, letting them escape. They are both awarded new chairs to keep them at their desks.
In Hitchcock & Scully, it was revealed that Hitchcock and Scully had worked Organized Crime back in 1986. They took down a mafia boss, Gio Costa, for running cocaine. With the help of their CI, they took down Costa and recovered a ton of coke along with duffel bags of cash. Captain Holt assigned Jake and Charles to look into the facts about what actually happened back them, since it was believed that Internal Affairs (IA) might be investigating the case. Due to some new findings were discovered about the bust of this case, both Hitchcock and Scully were given a year of desk duty.
- Scully has fallen for at least 20 Nigerian scams.
- Scully is trilingual.
- He is fluent in French. His parents forgot him in the Louvre in Paris when he was nine, and they didn't realize until they were back in Queens.
- He is fluent in Morse Code. His dad was a prisoner of war in Korea, and the only way Scully could communicate with him was in Morse Code.
- It is possible he could speak more than three languages
- Nobody at the precinct knows if Kelly is his dog or his wife due to the way he describes her, and neither is it revealed to the audience.
- He has had 3 heart attacks during a year in the 80's when he was addicted to cocaine.
- He also had a heart attack in the 70's when he used diet pills.
- He has had a pacemaker fitted.
- He has a blood pact with Hitchcock that states if Hitchcock dies then Scully will marry his wife, when they made the blood pact Hitchcock was already bleeding.
- Scully sends weird texts, due to touch screens not responding correctly to his fingers. He claims this is because he's been electrocuted so many times. 
- Scully often wears a napkin "bib" when he's eating.
- All of Scully's opera singing is Miller's own.
- Scully is constantly accidentally butt-dialing people.
- Scully is very good at putting jigsaw puzzles together, as shown in Safe House.
- Scully is lactose intolerant and diabetic, as revealed in Boyle's Hunch.
- Scully has seizures as revealed in The Honeypot. He threw away seizure medication instead of fidget spinner into a bin. Then he spun a fidget spinner and forgot they lit up and said it was a mistake.
- Alongside with Hitchcock,Scully have an impressive tracking skill that involves everything about food
- Scully likes to eat at Wing Slutz, especially the Marin Park location where he can get an extra drumstick in his Slutz bucket, as revealed in Hitchcock & Scully.