The event is sponsored by Glamour magazine's The Girl Project, which offers education help to more than 50 million girls worldwide.
Obama will be joined from the Newseum in Washington by "Black-ish" actress Yara Shahidi and Glamour editor-in-chief Cindi Leive.
Participating in the event will be girls in Washington, Jordan, Peru, Tanzania and the UK.
The event, with help from cosmetics giant Maybelline New York, kicks off a monthlong campaign by The Girl Project to raise money for education programs.