"Women's rights are something so inextricably linked with who I am, so deeply personal and rooted in my life that I can't imagine an opportunity more exciting," she said.
"I still have so much to learn, but as I progress I hope to bring more of my individual knowledge, experience and awareness to this role."
The Under-Secretary-General and Executive Director of UN Women, Phumzile Mlambo-Ngcuka, paid tribute Emma’s “intellect and passion”, stating: "We are thrilled and honoured to work with Emma, whom we believe embodies the values of UN Women.
"The engagement of young people is critical for the advancement of gender equality in the 21st century, and I am convinced that Emma's intellect and passion will enable UN Women's messages to reach the hearts and minds of young people globally."
Emma’s first task in her new role will see her act as an advocate for UN Women's HeForShe campaign, which calls for men and boys to stand up against inequalities faced by women and girls around the world.
Angelina Jolie has served as an ambassador for the UN’s High Commissioner for Refugees since 2001 and carried out over 40 field missions.