Pop star Justin Bieber's music video "Baby" has crossed 500 million views on YouTube and is the most watched ever on the video-sharing service that launched the boy music idol to fame.

The video, whose full title is "Justin Bieber - Baby ft. Ludacris," had logged 500.4 million views on Monday.

The video had also scored a whopping 1.1 million "dislikes" as compared to 578,000 "likes" from viewers expressing their opinion with simple thumbs-up or thumbs-down rankings at YouTube.

Bieber's clip topped a "Bad Romance" music video by Lady Gaga that had been viewed nearly 362 million times.

The top amateur video of all time at YouTube was "Charlie bit my finger - again," a 56-second snippet of a baby chomping on his bigger brother's forefinger.

The video had been viewed more than 296 million times, with 600,000 "likes," as of Monday.