Charles appointed Perry, 35, to the position Tuesday at the trust's royal annual reception and dinner at Banqueting House in London, also attended by his wife, Camilla, Duchess of Cornwall.
The trust said in a press release that Perry will work with its new Children's Protection Fund, which aims to combat child trafficking and abuse in India over the next five years.
Perry first met Charles at a British Asian Trust meeting in Mumbai in 2019. Perry, who also serves as a UNICEF Goodwill Ambassador, was keen to help after learning of the trust's mission.
"I am especially honored to be named an ambassador for the British Asian Trust and to use my voice to shine a light on the work that the British Asian Trust will be doing in South Asia, and to be a part of finding solutions to protect children from exploitation and abuse. Children are vulnerable and innocent and have to be protected," Perry said Tuesday at the gala.
India advisory council member Natasha Poonawalla will chair the new Children's Protection Fund. The Children's Investment Fund Foundation will match donations to the fund up to 25 million pounds.
Charles and British Asian business leaders founded the British Asian Trust in 2007 to combat widespread poverty, inequality and injustice in South Asia.
Perry released her fifth studio album, Witness, in 2017. She serves as a judge on the ABC reality competition American Idol.