- Alternate Character Interpretation: In "The Saint of Last Resorts," is John being honest with Anne Marie when he gives her the spiel about how no cost is too high to protect the innocent, especially if the innocent is a baby, or is he talking out of his ass because he knows she'll fall for it and do what he wants? Later on, is Anne Marie being honest when she repeats it, or is she just throwing it back in Constantine's face to add insult to injury when she shoots him to protect the children from the Invunche?
- Big-Lipped Alligator Moment: A three legged deer randomly appears in "Rage of Caliban" and nothing is said about it after the incident.
- Broken Base: Pre-release, the show got a rather nasty one after it was said that John would not be bisexual in the show, as the creators deemed it unnecessary to his character. Unfortunately, they also added "And besides, he sleeps with mostly women anyways." While there are some who didn't care (citing how John's romantic partners tend to die in the comics, how he only ever slept with one man in the comics, or that they would judge the show when it came out and not before), a lot of viewers (particularly people who are LGBT themselves, or sympathetic/supportive towards such) were upset at the bi erasure. It doesn't help that bisexuality in particular, especially male bisexuals, are largely ignored in media depictions, and that LGBT characters in comic books rarely get adaptations, especially ones that retain their LGBT status. While David Goyer was quick to note that they never said he wasn't bisexual, John was never once shown hooking up with men, only women.
- This ended up getting an Author's Saving Throw after Constantine was retroactively added to the Arrowverse and moved over to Legends of Tomorrow where he is explicitly depicted as bisexual, having a romantic relationship with another man.
- Cant Unhear It: Following his acclaimed performance in the series Matt Ryan is regarded as the Constantine and become the de facto performer. He has reprised his role as Constantine for all of the character's subsequent appearances with the children's series Justice League Action so far being the only exception.
- Complete Monster:
- "A Whole World Out There": Jacob Shaw evaded punishment after getting caught by transferring his mind from his body to a Pocket Dimension found during his occult studies, where he essentially became a god-like Reality Warper, able to live out his sick fantasies as much as he wanted. When a group of teenagers accidentally trespasses into his realm, he takes this as an opportunity to live out his sadistic pleasure even more. He starts hunting the teenagers in the real world by appearing on reflective surfaces, driving them nearly insane, and then brutally killing 3 out of 4 via impaling, dismembering with a knife, and suffocation. Afterwards, he keeps the souls of the deceased in his realm, where he keeps on torturing them and tells them that they will experience a never-ending circle of getting hunted down and killed by him, all just because he enjoys it.
- "Waiting for the Man": "The Man" is introduced as a Satanic redneck who abducted three little girls and murdered them, afterwards raising their spirits to make them his mindlessly devoted "brides". He sends them off to find another bride for him, and while waiting for them to return he brutally tortures and murders a bypassing, helpful man in a ritualistic way, for seemingly no other reason than being near him at the wrong time. It is revealed that "The Man" also murdered his real wife six years ago as a sacrifice for Satan. Later, John and his crew arrive in the nick of time, just before "The Man" was going to subject the fourth girl to the same horrific fate his three brides suffered. "The Man" is such a despicable individual that John Constantine and Jim Corrigan decide to outright murder him instead of just having him face the law.
- Cult Classic: The show has a strong online following, but apparently, it wasn't strong enough for NBC to renew it for a second season. Six months after NBC cancelled the show and Warner Bros. released the actors and staff from their contracts, fans have started a petition in an effort to get the series uncancelled on another network, especially after Constantine's guest appearance on Arrow.
- Ensemble Dark Horse: Anne Marie managed to win over a lot of fans despite her short appearance. This may have to do with the fact she's one of the more moral characters on the show, able to stand up to John, has a strong link with his character, and is played by the very lovely Claire van der Bloom.
- Growing the Beard: Audiences and critics alike thought the first few episodes to be So Okay, It's Average, but showing potential. But audiences and critics alike both agree that episode four, "A Feast For Friends", which introduces more of Constantine's moral problems and backstory, is when the show really started picking up steam.
- Harsher in Hindsight:
- The reluctance of Constantine to call himself a "Master of the Dark Arts" at first seems like a Running Gag, but the end of the pilot episode shows there is a very serious reason: his arrogance in assuming he was this and summoning a very powerful demon to take a lesser demon away, rather than exorcising said lesser demon instead, showed that he was, in his own mind, not worthy of calling himself a "Master", but rather the "Petty Dabbler" he calls himself in the show.
- John's promise that he is coming for Astra in the first episode becomes even more heartbreaking when, in Legends of Tomorrow, he does... only for Astra to have been corrupted by Hell in the meantime, causing her to take revenge on John and use him as an Unwitting Pawn.
- Hilarious in Hindsight: In "The Devil's Vinyl," John uses loud punk music in headphones to drown out the mind-controlling audio that's causing people around him to fight to the death. And he gets the headphones knocked out, forcing him to start fighting. Cut to almost one year exactly after the episode airs, and the finale of Jessica Jones does all of those same things.
- Memetic Mutation: John's Magic Card has been called Psychic Paper.
- Older Than They Think: Some fans unfamiliar with the comics think Papa Midnite's "Ace of Winchesters" is a reference to Supernatural. In fact it is an artifact created in the comics, specifically as the main plot device between the Hellblazer/Hitman crossover Garth Ennis wrote.
- The Scrappy: When the pilot was leaked, multiple critics online didn't like Liv, which helped cause her being written out. The AV Club and IGN both felt that Liv's departure was ultimately for the better. Considering that she was replaced by Zed, so did many of the fans.
- Screwed by the Network: Early restrictions on smoking and darker material hurt the first three episodes. Coupled with some out-of-order episodes (the Halloween episode airing four weeks after Halloween) and a lack of marketing saw low ratings, on an already bad timeslot (Friday nights). Just as ratings were picking up steadily each week thanks to word of mouth, NBC had already halted production. And then waited half a year to decide on the fate of the show.
- They Changed It, Now It Sucks!:
- Besides the above issue, some fans are also up in arms because the pilot mispronounces his name. The I sound towards the end if supposed to be long vowel, like "tyne" but they pronounce it "teen".
- Also, NBC's restriction against explicit smoking though John is famously a chain-smoker. The pilot tries to work around it like by showing only cigarettes being stubbed out. Later on this is completely dropped, as several episodes have explicitly shown John smoking.
- In a strange turn of events, some fans are taking umbrage with the fact that the show is taking more cues from the source material than the film. A case of 'They changed it back, now it sucks.'
- They Wasted a Perfectly Good Character: It's obvious that the decision of Liv not staying on the show was made very late in production of the pilot, with all the backstory built up for her going to waste. The plot of at least the first season still depends upon her involvement as well, since Constantine is following the markings she left behind on the map.
- The Woobie: John's father used to call him "Killer" and physically abuse him, due to his mother dying in childbirth.
YMMV / Constantine (2014)