Aziz Ansari does not appear in three consecutive episodes during the final season, "Mrs. Ludgate-Dwyer Goes to Washington", "Pie-Mary", and "The Johnny Karate Super Awesome Musical Explosion Show". He is seen in the next episode "Two Funerals", returning from a trip to New York.
"Beauty Contest" is the only episode in the series not to feature Nick Offerman, whose character is written off as recovering from his hernia in the previous episode.
Similarly, Aubrey Plaza is absent from "Kaboom", though her character's absence is not addressed.
A picture of Madam Secretary on Leslie's wall. Similarly, when Leslie meets Joe Biden in the fifth season, she thinks he's going to ask her to replace "Madam Secretary".
Tom's angry insistence on a high thread count in his bed sheets is a reference to Aziz Ansari's standup bit about buying Luxury Linens brand sheets, only to find out the package lied about the thread count.
Tom tells Ann that he couldn't afford to get toppings on two pizzas, because he's not Zuckerberg.
Nick Offerman is a real life carpenter, and his character Ron makes several references to projects he's actually completed.
One episode has Donna live-tweeting a movie, which is based on Retta's real life live-tweets of shows.
Like Aziz Ansari, Tom is an Indian American from South Carolina.
April being of half-Puerto Rican descent. However, in the real-life case of Aubrey Plaza, it's from her father's family, versus April's mother.
Donna evidently has relatives in Liberia; so does her actress, Retta. In fact, Retta (full name Marietta Sirleaf) is related by marriage to Ellen Johnson Sirleaf, first female President of Liberia.
Banned in China: Sony dared not broadcast the infamous episode "Sister City" (which dealt with a very point-on parody of Venezuelan military government officers) on its Venezuelan feed, and it's very improbable that the series even airs on open networks.
Cast the Expert: In possibly the strangest example, Jay Jackson, who plays Perd Hapley, is an actual newscaster with 22 years of experience rather than a natural actor. In fact, in every role he's done (including Dexter, Fast Five, and Scandal), he always plays a newscaster.
Casting Gag: Ron Swanson's crazed bitch of an ex-wife Tammy Two is played by Megan Mullally, who is Happily Married to Nick Offerman.
It's hard to blame him considering how undercooked a character Mark was, and then later was the odd man out when the series found its identity in season 2, but Paul Schneider has been honest in his bitter feelings about his experience on the show and that it left him with a pretty sour outlook on mainstream acting as a whole (he now selects low-key roles in independent projects and takes a lot of time off in between jobs). When the creators kept the door open for a return, he expressed an explicit lack of interest in ever reappearing again, which may explain why Mark slid into Un-person territory from season 3 onward.
The creators and cast as a whole seem to feel this way towards the first season. Aside from agreeing with the fans' consensus that the humor was weaker and the characterizations were spotty at best, they also rarely ever acknowledge it. At one point, during one panel between the cast, Greg Daniels brought up a moment between April and Andy in the episode "Rock Show", which he mentioned was in season 1, then gave a knowing pause at what he just said, causing everyone in the audience to laugh and Aziz Ansari to yell, "Don't bring up those shitty episodes, man!"
The Li'l Sebastian plush from "The Trial of Leslie Knope". An ad for it appeared in the bottom row of the original broadcast of the episode.
Leslie originally wrote the book Pawnee: The Greatest Town in America in "Born & Raised". Show writer Nate DiMeo eventually wrote it for real.
Mayfair Games is working to make Ben's game Cones of Dunshire (from the episode of the same name) a real product.
Deleted Scene: So very many. Although only intended to be a half-hour sitcom with 22-minute episodes, the series regularly shot enough footage for an episode twice the length. During Season 1, many of Aubrey Plaza's scenes actually got left on the cutting room floor, only to emerge when the DVD came out later.
Often, especially for the earlier seasons, the uncut versions of the episodes are the ones available on streaming sites like Hulu and Netflix.
Dyeing for Your Art: Chris Pratt was originally quite slim but decided to gain weight to play the schlubby Andy. He would then dramatically lose and gain weight throughout the show's run for other roles as his film career took off and he eventually became a genuine box office draw with Guardians of the Galaxy.
Enforced Method Acting: Chris Pratt revealed that when he needed to show up naked at Ann's door in "Kaboom", he was failing to elicit a proper reaction from Amy Poehler until he went completely naked without telling her. Her wide-eyed shock is the take they used.
Fake Nationality: New Zealander Lucy Lawless as the American Diane Lewis. Lawless may have lived in America a while, but you can tell sometimes.
In Memoriam: The message at the end of the series finale saying "We Love You, Harris. —The Parks Crew" is dedicated to writer-co-star Harris Wittels who tragically died on February 19, 2015, five days before it first aired.
Real-Life Relative: Will Arnett has a cameo as a creepy guy Leslie dates in "The Set-Up". He was then married to Amy Poehler (Leslie) in real life. Also, Nick Offerman (Ron) and Megan Mullally (Tammy 2) are married in real life.
Saved from Development Hell: This happened with a joke. A deleted scene from a town meeting featured a citizen complaining that an old sandwich she found in the park didn't have mayonnaise, and how this failed to meet her standards of a sandwich. The creators must have really liked the bit, because the scene was worked into a future episode.
In 2010, the show was brushed aside for mid-season replacement Outsourced, which was hated by critics and did not make it past a first season. The show's fifth season narrowly avoided being cut to 13 episodes as a precursor to cancellation, but the season was officially granted a full 22 episodes.
Averted with its renewal for Season 6, although the failures of every other comedy on the network and the ending of The Office forced NBC's hand. The only other comedy to survive was Community.
NBC got its final digs at the show by hustling it out the door, holding the final 13 episodes until the back half of the season, airing two per week and having it off the air before the end of February.
Not only did they blow through the final 13 episodes, they bumped the series finale from the show's usual 8 PM timeslot all the way back to 10 PM to make room for two hours of singing competition show The Voice. Way to Kick Them While They Are Down, NBC.
Star-Making Role: For Nick Offerman, Rashida Jones (coupled with The Office), Aziz Ansari, Aubrey Plaza, Chris Pratt (coupled with The LEGO Movie and Guardians of the Galaxy), Adam Scott and Retta. In other words, basically the entire cast other than Amy Poehler (who already had fame from SNL) and Rob Lowe, who also already had a career.
Late in the series, Jean-Ralphio Saperstein, played by Ben Schwartz, introduces his twin sister, Mona Lisa, played by Jenny Slate. Despite the actors not being related, they practically match the trope for Half-Identical Twins.
During the episode "Tom's Divorce", many viewers could not help but notice that the stripper Leslie hired (played by Cheryl Texiera) to give Tom a lap dance looked uncannily like Wendy (played by Jama Williamson). Definitely deliberate on the part of the casting department.
The London storyline came about as a way to keep Chris Pratt on the show while he was filming Guardians of the Galaxy in the UK — Peter Serafinowicz appeared on the show in that story while also being in Guardians with Pratt.
There's also a throwaway line in the season premiere about Andy giving up beer in order to explain Pratt's fitter physique.
The show makes use of varying degrees of improvisation. The most frequent example are the "addressing the camera" scenes with many jump cuts between jokes; these are usually the result of letting the actors run off-script (especially with Amy Poehler).
Series co-creator Mike Schur also said at a panel discussion that his favorite joke in the entire series — Andy's line "Leslie, I typed your symptoms into the thing up here and it says that you might have... Network Connectivity Problems." — was made up on the spot by Chris Pratt.
Word of God: Ron's nickname for Marlene Griggs-Knope was not specified in the script, and the nickname is heard in the episode as "the Iron-[bleeped] of Pawnee". According to Aziz Ansari's Twitter page, Nick Offerman improvised "the Iron Cock-Shredder of Pawnee" at the table read.
Deleted scenes and DVD audio commentary reveal that several Pawnee townspeople would become more heavily recurring characters in future episodes. These characters included Conspiracy Theorist Barry, anti-parks advocate Kate Spivak, and Andy's neighbor Lawrence. When the Pit 48 plot was deemphasized in the next season, the need for these characters diminished. However, Lawrence made several cameo appearances in later episodes. Barry appears very briefly in Season 2's "Sister City", though he only has lines in a Deleted Scene.
Even after the original plan for P+R being a spinoff of The Office was scrapped, there was an idea to create a connection for the two, where the Dunder-Mifflin copier would break, be fixed and refurbished, and then shipped to the Pawnee Parks and Rec department. It never happened.
A minor one: the character that developed into Ron Swanson originally had the surname "Knope" to reflect his stance vis-à-vis government, but then the creators decided to give it to the character that became Leslie for irony.
Originally the producers wanted Arnold Schwarzenegger to play Pawnee's Mayor Gunderson. Arnold was willing to do so, but couldn't while he was governor, so Gunderson became The Ghost instead. Gunderson did eventually appear near the end of the series, played by Bill Murray.
Adam Scott (Ben) auditioned for the role of Jim on The Office. Had he gotten the role, he likely would never have been on Parks.
Jim O'Heir (Jerry/Garry/Larry/Terry) auditioned for Ron Fucking Swanson. He admits he can't see anyone besides Nick Offerman in the role.
Mark was originally intended to periodically return to the series with a running gag of Why Do You Keep Changing Jobs? to emphasize the unpredictability of working for the government, but lack of interest in the character led to him being phased out of the universe entirely. Ironically, during the interview where this was stated, Mike Schur emphasized that Mark wasn't going to be wiped out of the show completely, which is exactly what ended up happening.
April was originally named Aubrey, making her The Danza.