Golant, who was appointed AMV BDDO's executive chairman in 2011 and chief executive in 2005, left in 2012 to be the CEO of TV production group All3media until September 2014.
She left All3Media after completing its sale for £550 million to a new joint venture between Liberty Global and Discovery Communications in September 2014.
Girl Effect was created nearly a decade ago by the Nike Foundation, the sportwear giant's charitable arm, in collaboration with the NoVo Foundation, United Nations Foundation and other partners.
Today's announcement coincides with Girl Effect severing its formal links with the Nike Foundation to become an independent organisation.
Ramzan Golant has also served on Prime Minister David Cameron's business advisory group from 2013 to 2015 and has served as a business ambassador for the Creative Industries of Britain. She currently serves as a trustee of Save the Children and sits on the advisory board of the Cambridge Judge Business School. She is also a non-executive director of Huntsworth Plc.
She said: "I can see tremendous opportunity ahead as business, government and NGOs combine forces to tackle the challenges facing girls living in poverty.
"Thanks to Nike Foundation’s groundbreaking and continued support, Girl Effect is already born different, is already creating insight rich, tech-enabled programmes and forging uncommon partnerships.
"There is clear conviction and a growing evidence base that girls can become pivotal change makers for themselves and their communities."