The 17-year-old singer was pictured topless in Hawaii with his singer girlfriend Selena Gomez sporting his the new ink - which is believed to spell "Yeshua", the Hebrew spelling of Jesus ' under his left armpit.
The design is thought to be the Canadian singer-songwriter's second tattoo after he had a small bird inked onto his hip last year, shortly after celebrating his 16th birthday in March.
Following Justin revealing his debut tattoo, the 'One Time' singer's fans bombarded twitter with positive comments.
One wrote: "Justin Bieber has a tattoo? That's hot."
And another tweeted: "Whenever my dad tells me I'm a disappointment for having a tattoo, I will remind him that Justin Bieber, 16, has one."
Justin's recent inking may have been a present to himself after he picked up six accolades at the Billboard Music Awards on Sunday night (22.05.11) in Las Vegas.
He won prizes for Top New Artist, Top Pop Album for 'My World 2.0', Top Social Artist, Top Digital Media Artist, Top Streaming Artist and Top Streaming Song (Video) for 'Baby'.