Teen pop sensation Justin Bieber turns 18-years-old today. Fans from all over the world are celebrating the Canadian singer's birthday as Happy National Bieber Day on twitter. Thousands from all over the world have posted their birthday well wishes on Twitter.

For the big 1-8, Bieber celebrated by appearing on The Ellen DeGeneres show yesterday. The Bieb's surprised fans and audience members by announcing that he is releasing his new single Boyfriend, on March 26th. The singer received a surprise of his own when his manager of five years, Scooter Braun, gifted him with a brand new, and very rare car, a Fiskar Karma.

To celebrate Justin Bieber's legality we composed a list of the funniest birthday tweets from fans. Check out the hilarious birthday tributes, as well as the Harry Potter fans who don't appreciate the singer sharing the same birthday as Ron Weasley.

  • Happy 18th Birthday Justin Bieber. Don't worry man, puberty can't be that far away now. - Mario Balotelli
  • My teacher asked the class: What is it today?and a boy shouted Its Justin Bieber's birthday. Me enjoying this class right now lol - Happy BDay Justin
  • Happy Birthday to the king. No, not Bieber, Ron Weasley. - Dumbledore's Beard
  • Decked out in my Purple shirt and Purple and White Converse @justinbieber HAPPY BIRTHDAY!! AND NATIONAL BIEBER DAY!! :) - jbieberblasters
  • Keep Calm and Say Happy Birthday Justin Bieber?- Biebsly
  • Happy birthday, Justin Bieber! You're officially not a 'Baby' anymore... go get with your 'Favourite Girl' today! - VH1 India
  • #itsTimeForYouToRealize that what really matters is that it's Ron Weasley's birthday. Not that Justin Bieber is 18. Muggle please.
  • @justinbieber Dude always, excited for tomorrow. When chuck norris turned 18, his parents moved out HIS house :) - Ryan Seacrest
  • @justinbieber Dude always, excited for tomorrow. When chuck norris turned 18, his parents moved out HIS house :) - iTunes Belieber
  • Justin is OFFICIALLY 18 -- Happy National Bieber Day! 18 sounds so different to 17... It sounds so... grown-up....... #mybaby - Biebsdiction
  • Happy National Bieber Day? lol Oh, man. I wish I were famous so fans could falsely name a day a national holiday after me! - lackadaisy_leah
  • The awkward moment when you're more excited for Justin's birthday. LOL Happy National Bieber Day ! LEGGO - TheBieberJonas
  • Happy National Bieber Day? FOUR MILLION POINTS FROM TWITTER! - SevSnapeProf
  • Happy National Bieber Day! Thou shall not have school today due to over sadness, excitement and happiness because our baby Justin's 18. - bieberismyfav