You may know her better as a Disney star or rock singer, but now Selena Gomez has become the youngest ever ambassador for the charity Unicef.
The 17-year-old star of Wizards of Waverly Place said her trip to Ghana, in Africa, to see the work being done to help kids there was "life changing".
Last year, Selena raised about $700,000 (£440,000) for Unicef's youth volunteer programme in Ghana.
This year, she says she's hoping to make it a million dollars - £629,000.
Unicef stands for the United Nations Children's Fund.
It looks after the needs of children and mothers in developing countries around the world.
Selena, who used to date Nick Jonas, said she felt "very honoured" to have a voice that kids listen to.
"I had people on my tour asking me where IS Ghana, and they Googled it and because I went there, they now know where Ghana is," she said.
"So it's pretty incredible."