The award – handed out by London-based organisation RAW in WAR to honour women working to help those trapped in conflict – is named after crusading Russian journalist Anna Politkovskaya who was gunned down in Moscow on October 7, 2006.
Vian Dakhil has given "a voice to the many Yazidi and Iraqi women and girls whose voices cannot be heard," the organisation said in a statement.
Dakhil, the only Yazidi legislator in Iraq, welcomed the award but called for greater attention to be given to the plight of the Yazidi minority in the face of the onslaught by the Sunni militants from the Islamic State (IS) group.
"It is a pleasure for anyone to be honoured with an award, but it is rare to see a Yazidi person who can feel happy from the bottom of their heart due to the fact that our girls, women and children are in captivity as hostages of the most dangerous organisation in the world," she wrote in an acceptance speech.
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Yazidi women kidnapped by IS jihadists in Iraq have been taken to Syria, forced to convert and sold into marriage to militants, rights groups say.
In August, IS captured Yazidi villages in the area of Mount Sinjar, prompting an exodus of the minority amid reports of executions and the abduction of women.
Last year's Anna Politkovskaya prize was given to teenage Pakistani activist Malala Yousafzai, who was shot by the Taliban for insisting on the right of girls to get an education.
A reporter at liberal newspaper Novaya Gazeta, who had been a fierce critic of the Kremlin's tactics in Russia's Chechnya region, Politkovskaya was gunned down at age 48 in the lobby of her Moscow apartment block.
A Russian court in June jailed five men for their roles in her murder, but those who ordered her killing have never been identified.