Justin Bieber is all grown up! No wonder teen queen Selena Gomez is in love.

The 18-year-old singer has released the full video for his latest single "Boyfriend" ... and we are lovin' it!

And who knew Biebs had those dance moves? Looks like another Justin Timberlake in the making.

JB's album Believe will be released in the UK on June 18 and in the US on June 19.