Sam and Dean

In this shot from behind the scenes on 1.04 Phantom Traveler , a small tattoo can be seen on Dean's upper arm. This tattoo never appeared in the show.

Following Sam's possession by Meg in 2.14 Born Under a Bad Sign, Bobby gives Sam and Dean each a charm amulet which features a symbol which will stop demonic possession. In 3.12 Jus in Bello, the boys reveal that they have had these anti-possession symbols tattooed on their chests.

Sera Gamble on the tattoos origins.

FFN: Those matching tattoos are pretty cool. How long has that been planned?

SG: I remember talking about it with Ben Edlund last season, while Cat was writing "Born Under A Bad Sign." We agreed that if we were Sam, the first thing we'd do is take that anti-possession amulet and head for the nearest tattoo parlor. He reminded me of it while we were working on “Jus in Bello,” because breaking out the amulets was an important story point in that episode. So I stuck it in there, and it made for a nice moment. It’s like, of course Sam and Dean have matching tats. How could it be any other way? By the way, I'll be convinced we're truly a cult hit when a fan gets the same tattoo.

Little did Sera know, that fans had been getting tattoos since early on in the show's run.

See Fan Tattoos for a gallery of Supernatural inspired tattoos from fans. The anti-possession tattoo is one of the most popular designs.

In 4.18 The Monster at the End of This Book, this phenomenon is referred to when Sam and Dean reveal their tattoos in order to pass as avid fans. In response the publisher of the Supernatural books by Chuck Shurley, reveals she has the same tattoo -- on her ass. While not named in the episode, the publisher's name was Sera Siege, named after writers Julie Siege and Sera Gamble -- as mentioned in this interview by Sera Gamble.

In 9.10 Road Trip Castiel removes Sam's tattoo at Dean's request, so that Crowley can possess Sam in order to help him expel Gadreel. At some point Sam has the tattoo reapplied and it is next seen in 13.02 The Rising Son, when he and Dean take Jack to get tattoos. He describes it to the tattooist as "kind of like a family crest."



Variation in Sam and Dean's tattoo appearance

Season 3 Season 4 Season 5-6

Season 8 Season 9

The boys anti-Possession tattoos first appear in 3.12 Jus in Bello. As pictured you can see the bottom two spokes of Sam's tattoo appear different to the bottom two on Dean's tattoo, based on where the lines are broken. Sams tattoo arm breaks on the very bottom side of the star point, where as Dean's is broken between the two arm sections of the bottom right star point. This appears to be simply because they are placed at a slightly different angle on the boys' bodies.

When we see the tattoos again in 4.18 The Monster at the End of This Book, Sam's tattoo is seen very clearly and now matches the original design Dean had in Season 3. Unfortunately, Dean's tattoo is not fully visible, however if you look closely you can see it appears to be upside down, based on where the circle is being broken by the second star point. There is only one arm on the design that can break through the circle without breaking any other star point arms, and that is the bottom left star point when looking at Dean's original tattoo in 3.12 Jus in Bello.

Sam's tattoo still matches Dean's Season 3 tattoo in 5.03 Free to Be You and Me as he talks to the illusion of Jess, as well as during the shirtless exercise scenes at the beginning of 6.03 The Third Man.

During Season 7 we see Dean's tattoo again in 7.13 The Slice Girls, when he has a one night stand with Lydia. His tattoo is very difficult to make out in the scenes and appears to have rotated position again. It is too difficult to make out the breaks in the star point arms to compare it to his Season 3 tattoo.

Later in 8.02 What's Up, Tiger Mommy? Sam shows his tattoo again upon Dean telling Kevin and Linda Tran that they will have to get tattoos. Sam's tattoo has returned to the original design from 3.12 Jus in Bello and again does not match Deans. It is difficult to see, but on close inspection the tattoos in progress on Kevin and Linda both appear to match Sam's tattoo in this episode at this point.

We see Kevin's tattoo again in 9.06 Heaven Can't Wait, and it has changed to match Dean's original Season 3 tattoo. Dean's tattoo is also visible again when Abaddon threatens to remove it in 9.02 Devil May Care. It matches his original design in Season 3, but again like Season 4, it is upside down.

Other characters

Charlie Bradbury

In 7.20 The Girl with the Dungeons and Dragons Tattoo Charlie Bradbury reveals she has a tattoo of Princess Leia in her slave girl bikini astride a 20-sided dice (which are used in RPGs). In a scenario familiar to many fans, she claims she got it while drunk at Comic-Con.

During the airing of the episode, the phrase #DandDtattoo trended on Twitter (Source).



Kevin and Linda Tran

In 8.02 What's Up, Tiger Mommy? Sam and Dean make both Kevin and his mom Linda Tran get anti-possession tattoos at the Inked Pig Tattoo Parlor. Linda admits its not her first. Later Plutus' assistant Beau burn off Linda's tattoo so that Crowley can possess her. During 9.06 Heaven Can't Wait, Kevin's tattoo is visible as he draws his blood so Crowley can call Hell.

Castiel

In 9.03 I'm No Angel after Castiel becomes aware that angels are hunting him, he gets a tattoo in Enochian which will make him unable to be tracked by angels. This is similar to the Enochian sigils he burned into Sam and Dean's ribs for the same purpose in 5.01 Sympathy for the Devil. However, this tattoo just jams him from being sensed by an angel's normal means of sensing people; Ephraim is able to locate him by sensing his pain, showing the tattoo doesn't block everything.

Arthur Ketch

Arthur Ketch has a cross tattoo on his right hand. This disappears after his resurrection, presumably removed to maintain his facade as "Alexander Ketch."

Cross tattoo on Mr Ketch's right hand

Jack

In 13.02 The Rising Son, Sam and Dean conclude that if the prophet Donatello Redfield could find Jack then others will be able to, so they take him to have protective symbols tattooed. When the tattooist questions Jack as to whether he is okay with getting the design's, Sam shows his tattoo and says "We’re brothers. It’s kind of like a family crest." At the first touch of the needle, the pain causes Jack to throw the tattooist across the room. The designs are eventually completed but Jack's body makes them vanish.



Mary Winchester

In 14.11 Damaged Goods, Mary shows Nick that she has gotten an anti-possession tattoo on her stomach at some point as proof that she can't be used as a meatsuit for the demon Abraxas.

Sam Smith tweeted this photo of Mary's tattoo





Actors

Jensen

In October 2017, Jensen got a tattoo at Forever Inked Studio in Vancouver. The tattoo is on his left bicep and features a bird in flight among rays of sunlight. Jensen posted an image of the work on Instagram explaining that it was "For my daughter JJ. Aka J-Bird or simply “Birdie”."

In October 2019, Jensen got a tattoo also on his left bicep, for his twin Zeppelin and Arrow. It featured an arrow wrapping around his arm, with a zeppelin knot in the middle.



Jeffrey Dean Morgan, Jensen and Jared

Jeffrey Dean Morgan, Jared and Jensen get friendship tattoos

On 5th October 2019, Jeffrey Dean Morgan married Hilarie Burton. The two have been together since introduced by their respective friends co-stars Jensen and Danneel (One Tree Hill). The ceremony was officiated by Jensen and JDM's current costar from The Walking Dead Norman Reedus.

At the wedding Jeff, Jensen and Jared then got matching tattoos. They are stylised crowns that symbolises three kings, and the 3 peaks are a W for Winchester. On his Instagram post JDM said " Hilarie and I weren't the only ones joined for life. Jared, Jensen and myself will forever have a bond that is both special and permanent."