Known for supporting gay rights, AIDS and poverty, Gaga focused much of her effort in 2011 on putting an end to bullying, even bringing her fight to the White House. This year, she also set up the Born This Way Foundation, which aims to empower youth.
Bieber continued his admirable work with Pencils of Promise this year, an organization which has built 41 schools in Laos, Nicaragua and Guatemala, founded by Adam Braun -- brother of Bieber's manager, Scott "Scooter" Braun. In the last 12 months, the 17-year-old released a perfume in his name, as well as a holiday album titled Under The Misteltoe, donating a portion of proceeds to charity. Among the organizations to receive support from Bieber's golden touch this year are the Make-A-Wish Foundation, Toronto's Daily Bread Food Bank and Children's Wish Foundation, as well as Whitney Elementary School in Las Vegas, Nevada, to name a few. For a more complete look at Bieber's charitable holiday season, click here.
Newlyweds Blake Shelton and Miranda Lambert came in at No. 14, while recently separated couple Ashton Kutcher and Demi Moore share the No. 12 spot. Other do-gooder couples include Will and Jada Pinkett Smith (No. 4) and Brad Pitt and Angelina Jolie (No. 8).
"There are some interesting trends from this year's list," says Aria Finger, COO of DoSomething.org. "It's dominated by young celebrities and we also see so many couples. Last year the list had its first power couple, Ashton and Demi, and this year there are a total of four couples. Doing good is definitely fun in groups."
For the first time, DoSomething.org incorporated Facebook voting to help determine the impact of celebrities reaching an audience with their cause. Criteria required stars to do more than simply give money, but to take action such as building houses, writing articles or founding an organization. One Tree Hill actress Sophia Bush was voted the first ever "fan favorite" by Facebook users.
Other entertainers making the list are Matt Damon, who held the No. 1 spot in 2009, Shakira, Lea Michele, Nick Cannon (sans wife Mariah Carey), Daniel Radcliffe, Taylor Swift, Demi Lovato and Leonardo DiCaprio.
"There are a handful of other celebrities who just missed the cut-off this year," Finger notes. "We look forward to seeing what they will do in 2012."
Among the celebs on her radar for next year are Jay-Z and Beyonce, Rihanna, Justin Timberlake, Zooey Deschanel, NFL star Tim Tebow and Bieber's girlfriend, Selena Gomez.
View the complete list below and for more on each honoree and their causes, visit DoSomething.org.
1. Lady Gaga
2. Justin Bieber
3. George Clooney
4. Will & Jada Pinkett Smith
5. Leonardo DiCaprio
6. Matt Damon
7. Ellen Degeneres
8. Brad Pitt & Angelina Jolie
9. Dwight Howard
10. Demi Lovato
12. Ashton Kutcher & Demi Moore
14. Blake Shelton & Miranda Lambert
15. Nick Cannon
16. Lea Michele
17. Daniel Radcliffe
18. Miley Cyrus
20. Taylor Swift