Jacksepticeye is a youtuber on youtube with currently 14,181,507 subscribers. (Will update the subscriber counter every week.)
The nickname “Jack” comes from his childhood. His mother and siblings gave him the nickname because in Ireland, another name of Seán is John, and another way to spell John in Ireland is Jack. The term “SepticEye” also came from his childhood. When he was still in school, he got a severe injury to his eye which later became infected, and his friend began calling him "JackSepticEye", after figuring out that Seán's mother called him Jack. Seán would later use the nickname as his YouTube username.
Seán lives in Athlone, Co. Westmeath, Ireland, and lives in an apartment in the city. He used to live with some friends (they moved), they did appear in a vlog once. He is very well known for his green hair, and is the second most popular "celebrity" in Ireland.
Seán attended college twice in Ireland, the first time (in Music Technology) he did not finish college, but the second time (in Hotel Management) he returned, he graduated with the degree. Jack has an energetic personality, and enjoys playing all sorts of games ranging from AAA games, to flash games, with his favorite games being Shadow Of The Colossus, DARK SOULS and Undertale.
He sometimes speaks Irish in his videos, such as various religion songs, and some phrases in Irish (Here are some examples).
He lived in the countryside with his parents as a kid. Later on, he lived in a cabin in the woods with his parents, grandparents, and siblings. Jack has two sisters, and two brothers, all of which are older than him.
His three favorite foods are cookies, cakes and ice-cream.
He first put a webcam in the video Amnesia the Dark Descent – WATER ASSHOLE – Walkthrough Part 3 Gameplay/Commentary/Facecam, and from there he started putting it in almost every video.
He started saying "Top of the mornin' to ya, my name is jacksepticeye.." in the video Maere: When Lights Die - HUGE SCARES - French Indie Horror game - Gameplay/Commentary. Also, in that video he first started using his outro music by TeknoAXE called I'm Everywhere.
MIISSTER WILLSSON!!!!!!! (Hello Neighbor)"MOTHER APE A**" (Happy Wheels)"Oh...That's all broken ankles!" (When a character falls from a height, usually in Parkour games)"F**KIN' HELL!" (Whenever stressed or failing at a game)"Top of the mornin' to ya laddies, my name is jacksepticeye and welcome (back) to [game]! (current intro)"Hello, all you beautiful people. My name is jacksepticeye." (old intro)"Hey, hey, guys, what is going on? I am back for another ___________." (first intro)"C-C-C-C-COMBO BREAKER!" (When an in-game character performs a multi-kill.)"SCREW YOU BILLY!!!" (When Billy dies, gets injured, or when Billy does something that Jack doesn't approve of) (At random times when Billy is seen)"Speeeeeed is keeeey!" (Mostly in Happy Wheels, Turbo Dismount and Skate 3, but pretty much every game where speed is related)"HAAAAAAAPPY WHEEEEEEELS!!!" (In the start of his intro, where he is stating the game, if he is playing Happy Wheels)Calm your tits, *name of a character or person*!” (Whenever jacksepticeye panics)"GO, BILLY, GO!!!" (When he does a bottle run in Happy Wheels)"Well, see ya later, Billy!" (Whenever he leaves Billy behind in Happy Wheels)"YOU WANNA TUSSLE?!?" (When a character wants to fight him)"NOTHING STOPS....THE SQUATCH!!!!" (When he uses the "Sasquatch" in Turbo Dismount)"OOOOOWWWWW PINK LIGHTNING" (When he uses the pink tricycle in Turbo Dismount)"YOLO B***HES!" (When he does something reckless)"Blasphemy of the highest order!" (When he makes a mistake)"LIKE A BOSS!" (when he gets a difficult thing done)"Thread the needle!" (When he attempts something that requires precision)"LOOK AWAY CHILDREN!!! [Covers web cam]" (When he sees something that is mature)"Flips for days!" (When Jack sees a character [in any game] doing flips)"F**KA YOU, GAME!" (When he has either outsmarted a game or when he is pissed off at a game [South Park Reference])"I DON'T WANT YOUR COOKIES!" (Whenever there is a creepy girl in a game)"And a hop, and a skip, and away we go!""F**K IT!" (When he fails at something)"Look at this sexy beast!" (Usually in Kerbal Space Program, when he creates something he labels as beautiful/majestic)"Hey Ma!... MA!! [says what is happening while pointing finger at screen]! 'S awesome...!" (When he sees/does something crazy going on in game)"TWISTY NIPPLE FRESHNESS!/TWISTY FRESH NIPPLES!/MY NIPPLES ARE SOOOO TWISTY FRESH RIGHT NOW!" (When he is excited about something)"Well that does it for this episode of [game on screen]!/Well I'm going to leave this episode here! If you liked it, punch that like button in the face, LIKE A BOSS! Aaand, high fives all around! (does two high fives in the air while making high five sounds). But thank you guys and I will see all you dudes...IN THE NEXT VIDEOOO!" (Outro)"BALLS? I LOVE BALLS!" (When something mentions balls or when he does anything involving balls [As in circles])"Limber, loose, RUBBER GOOSE!" (In Happy Wheels. in a level where you have to move a lot, such as ball falls and jet falls)"SHOW ME YOUR GAME FACE... GERRERRRRRRRR!!!" (Whenever he's about to attempt something very difficult)"GO JACKY BOYYYY!" (In Turbo Dismount, when using his face on a character at the beginning of a level)"OFF ROADING B***HES!" (When usually in Grand Theft Auto V he goes off roading in his car)"LOOK AT THESE +1 BICEPS!" (whenever strength is involved)" 'STICKY BOMB! " (When he is playing Grand Theft Auto V and throws a Sticky Bomb)"BOOPER DOOPER!!" (When he's really excited, or he doesn't have anything else to say)"Go away, smelly!" (When an enemy comes near him)"STOP WINKING!!"(When he plays Cleverbot and Evie or Boibot starts winking)"Let me sniff your butthole!""BALLS-A-ROONEY-TOONEY!" (When he messes up)"I'm a whale biologist, damnit!"(When talking about animal or human anatomy)"A-Wooshie woosh!" (Undertale)"That is bull to the sh*t to the bullsh*t!""aShimmy Shammy, aShimmy, aShimmy Shammy" (Super Mario Maker)"DETAINED!!" (Papers, Please)"GLORY TO ARSTOTSKA, GREATEST COUNTRY, MOTHER PROUD!!" (Papers, Please)"GLORY GREATEST COUNTRY!!" (Papers, Please)"Sweet!" (Whenever something good or cool happens when he plays Ori and the Blind Forest)"Here comes fun!" (When an object, sometimes actually fun or sometimes sarcastic, is thrown at him or an enemy. Used most commonly in CHKN)"Oh me nads!" (Used to referencing balls)"Now we're/you're sucking diesel" in an Irish accent (When he does something really well after continuously trying)"F**KING SNOWPLOWS!" (Turbo Dismount)"Just like a Majestic Eagle Sasquatch""SUCK MY TESTICLES/ARSE!" (Whenever something fails/dies)"CAN'T WE ALL JUST GET ALONG?" (when people aren't "getting along")"Peistagesistos!""I'm Trippin' Balls!!!" (When he's playing a game and everything goes weird, like an acid trip, his username when playing a multiplayer game with friends)""Christ on a bike cycling to mass on a Friday"""Christ on a bike" (when something crazy/annoying happens)""When In doubt, Segway Steve!" (While playing happy wheels, mostly with spike falls)""I'm trying to find stuff to fucking kill myself."" (Who's Your Daddy)""If you liked it punch the like button up the ASS like a boss!!"" (Happy Wheels - Part 1)""Some people call you ugly, but I call you the FUCKING FATTEST BITCH EVER!""(Happy Wheels - Part 2)""OH HAIRY NIPPLES WRAPPED IN PLASTIC!!!"" (Happy Wheels - Part 95)""Stop saying fetch it's never going to happen!"" (Happy Wheels - Part 99)""No one dies a virgin Felix, life fucks us all."" (Gential Jousting)""Where's my penis equality?"" (Genital Jousting)""It's just in my ass."" (Happy Wheels - Part 100)""Now all you have to do is... NOT SUCK A DICK!!"" (Happy Wheels - Part 100)""My fingers smell like ass..."" (Happy Wheels - Part 100)"Mark, red means stop so STOP BREATHING!" (CRINGEMAS CHARITY LIVESTREAM)"They better be long or really hard." (Clustertruck #18)