Malala Yousafzai has told Emma Watson the actress's speech to world leaders made her change her mind about not describing herself as a feminist.
The 18-year-old met the Harry Potter star at the premiere of a documentary film about her called He Named Me Malala.
Ms Yousafzai, a Nobel Prize winner, said she initially thought feminism was a "tricky word" but now believes everyone should be a feminist.
Watson, a United Nations global goodwill ambassador for women, gave a speech to the UN last year to launch her He for She campaign, aimed at encouraging men to speak up for women's rights.
Ms Yousafzai began speaking out on education for girls in 2009 when she was just 12.
She was 15 and on her way home from school in the Swat Valley, Pakistan, when she was shot in the head in October 2012 for speaking out against the Taliban and its ban on female education.
Ms Yousafzai said her father Ziauddin had been an "example to all men" and called himself a feminist.
She added: "It has been a tricky word. When I heard it the first time I heard some negative responses and some positive ones. I hesitated in saying am I feminist or not?
"Then after hearing your speech I decided there's no way and there's nothing wrong by calling yourself a feminist. So I'm a feminist and we all should be a feminist because feminism is another word for equality."
Men "have to step forward" to promote equality of the sexes, she said.
Watson posted a video of the interview on her Facebook page and said she found Ms Yousafzai's admission "moving".
She said: "Perhaps the most moving moment of today for me was when Malala addressed the issue of feminism. To give you some background, I had initially planned to ask Malala whether or not she was a feminist but then researched to see whether she had used this word to describe herself.
"Having seen that she hadn't, I decided to take the question out before the day of our interview. To my utter shock Malala put the question back into one of her own answers and identified herself. Maybe feminist isn't the easiest word to use... but she did it amyway.
"I've spoken before on what a controversial word feminism is currently. More recently, I am learning what a factionalised movement it is too. We are all moving towards the same goal.
"Let's not make it scary to say you're a feminist. I want to make it a welcoming and inclusive movement. Let's join our hands and move together so we can make real change. Malala and I are pretty serious about it but we need you."
Ms Yousafzai has been living in Birmingham with her family since the assassination attempt.
She is studying for A-levels in history, economics, maths and religious studies and plans could include going to Oxford or Stanford University in California.