Lady Gaga tops a new Forbes list of the best-paid celebrities under the age of 30, with Justin Bieber, Katy Perry, and numerous other artists placing highly on the report.

The magazine reports that Gaga's concerts raked in $170 million between May 2010 and May 2011, the start and end points for the survey. Her personal share was an estimated $90 million, easily outpacing the rest of the field. Gaga also topped the Forbes Celebrity 100 list, which ranks celebs based on earnings and star power.

In second place on the young earners list is Bieber, who at 17 is the youngest performer featured. He pulled in an astounding $53 million over the last 12 months. Imagine that -- the Biebs could retire already if he wanted.

Musicians make up a substantial portion of the Top 10, with Taylor Swift ($45 million) ranking fifth, Katy Perry ($44 million) in sixth and Beyonce ($35 million) in eighth. Rihanna ranks 11th with $29 million.

Other musicians inside the Top 20 include Miley Cyrus (16th), Carrie Underwood (19th) and Lil Wayne (20th). The highest-ranking non-musician is basketball star Lebron James in third place, followed by tennis champion Roger Federer in fourth.

Forbes calculates that the Top 20 young celebs earned a total of $690 million over the previous 12 months. Nope, we can't fathom that kind of money, either!

Watch Lady Gaga Perform 'The Edge of Glory' and 'Judas' on 'Saturday Night Live'