Justin Bieber, Bruno Mars are Top 30 Under 30

Pop star Justin Bieber, singer Bruno Mars, and rapper Wiz Khalifa have been named among the 30 highest achievers under the age of 30.

Bosses at Forbes magazine annually recognise a handful of celebrities for their successes in a broad range of categories, and this time the trio was among those honoured for their accomplishments in music, alongside Lady Gaga and soul sensation Adele.

Former child stars Mary Kate and Ashley Olsen were celebrated for their fashion design skills, while Olympic gymnast Gabby Douglas and American basketball icon LeBron James were chosen for their athletic abilities.

Rounding out the group of young pioneers were U.S. TV comedienne Kate McKinnon and Facebook.com founder Mark Zuckerberg, and editor Michael Noer admits his fellow writers had a hard time finalising the list, "These are really amazing people and they are doing amazing things. It makes you very hopeful about the world."