Prince Harry and Meghan Markle will attend a women’s empowerment reception, hosted by Foreign Secretary Boris Johnson.
The couple, who will wed on May 19, will join charities and organisations aiming to promote global gender equality.
The event is being held as part of the Commonwealth Heads of Government Meeting in London.
Mr Johnson will launch his Platform for Girls Education, a group of 12 influential figures from across the Commonwealth who will drive forward the political momentum on girls' education.
More than 130 million girls around the world are not in school and girls in conflict zones are twice as likely to be out of school compared to boys.
Prince Harry and Meghan Markle attend Commonwealth Youth Forum
American former actress Ms Markle is known for her commitment to gender equality and empowering women, previously being a Women's Advocate for the UN.
When she was 11, she persuaded a soap manufacturer to alter an advert after she wrote a letter to then first lady Hillary Clinton complaining that it implied women belonged in the kitchen.
Ms Markle also visited the Myna Mahila Foundation in India last year, and wrote about its work to combat period poverty, highlighting how the schooling of young women in India is disrupted when they are menstruating.
Harry and Ms Markle have nominated the organisation as one of the seven charities well-wishers could donate to, rather than buying them wedding gifts.
Charities at the reception will include the Malala Fund, Plan International, the Varkey Foundation and Code Camp.
Additional reporting by Press Association.
