Gomez is the star of Disney Channel's "Wizards of Waverly Place." She has also appeared on "The Suite Life of Zack & Cody" and "Hannah Montana."

This month marks the 58th anniversary of "Trick-or-Treat for UNICEF," a program that encourages U.S. children to raise money for children around the world while they collect their own candy on Halloween.

"I am extremely excited to be this year's 'Trick-or-Treat for UNICEF spokesperson,'" Gomez said in a statement. "I want to help encourage other kids to make a difference in the world and show them that 'Trick-or-Treat for UNICEF' is such a great, fun way to get involved."

"We are thrilled to have Selena be a part of the 'Trick-or-Treat for UNICEF' program this year," said Caryl Stern, president and CEO of the U.S. Fund for UNICEF. "Young people can relate to Selena, and she is a great role model who we believe will greatly enhance the visibility of the program."

The "Trick-or-Treat for UNICEF" program has raised more than $140 million to date, the organization said.