The England captain joins world leaders in New York for the UN's Sustainability Development Goals (SDGs) Summit, and her message will be, 'Don't leave girls behind'.
The Arsenal player will appear at a one-on-one talk with girl's education activist, Vee Kativhu.
Williamson will speak about her recent visit to Za'atari in Jordan, the largest Syrian refugee camp in the world, where she witnessed what football has done for girls and communities there.
"Sport has the power to change lives but it's still not a level playing field for so many girls around the world. Football definitely changed my life," Williamson said ahead of her address.
"After visiting the Za'atari refugee camp, I've seen first-hand how our football programme, Coaching for Life, is helping the girls in the camp cope better with the challenges they face.
"Through The Arsenal Foundation's work with Save the Children, we've shown in Za'atari how we can empower girls through sport, and how boys can play an active role with us on that journey."
