Girls' rights activist Betty Makoni of Zimbabwe won two main categories of the annual World's Children's Prize for the Rights of the Child on Friday.
Myanmar's Cynthia Maung and India's Inderjit Khurana shared an honorary award.
The 1 million kronor (108,000 EUR; US$145,000) award is split into three parts, and honors efforts to better the lives of children worldwide. More than 5.2 million children took part in this year's global vote of which all three candidates received more than 1 million votes each, the award committee said.
Makoni, founder of the Girl Child Network in Zimbabwe, was awarded the Global Friend's Award for her work to help Zimbabwean girls escape trafficking, sexual abuse, child labor and other assault.
She was also announced winner of The World's Children's Prize, which is decided by a jury of 15 children who have been exposed to child labor, war or poverty.
"I feel humbled," Makoni said as she was given flowers at a ceremony in Stockholm. "This is the job I've always wanted to do."
Maung, who fled her native country 18 years ago and runs a medical clinic in Thailand providing free health care for refugee children, said it was one of the "most beautiful days" in her life.
Khurana, honored for starting the Ruchika organization that runs schools and nurseries for poor children in India, received loud applause and said the fight for children's rights must continue.
"I won't say it's my dreams coming true, because dreams shouldn't come true that fast. I have a long way to go and I have a great commitment," she said.
The awards were set up in 1999 by the Swedish Children's World Association to recognize the outstanding contributions of those who defend youth rights.
Sweden's Queen Silvia will host an awards ceremony for the winners at Gripsholm's castle outside Stockholm on Monday.
Last year's prize went to the Rwandan orphans' organization, The Association of Orphan Heads of Households, the Canadian activist Craig Kielburger and the Dalai Lama's sister, Jetsun Pema.