Duchess Catherine is "passionate" about raising awareness of children's mental health.
The royal - who has two children, Prince George and Princess Charlotte, with husband Prince William is joining forces with HuffPost UK to launch Young Minds Matter and the site's co-founder Ariana Huffington has praised Catherine in a new blog post.
She wrote: "We're honoured and thrilled to welcome a very special guest editor, Her Royal Highness The Duchess of Cambridge. She'll be joining editors at HuffPost UK to launch Young Minds Matter, a new global initiative to raise awareness around mental health and children. Together, we want to open up the conversation around mental health - an issue that's too often stigmatised and discussed only in whispers, if at all.
"The Duchess is passionate about opening up the conversation around young people and mental health."
Ariana also praised Catherine for "shining a light on this issue".
She wrote: "The Duchess, as the world knows, is herself the mother of two young children, and knows the importance of shining a light on this issue, especially for the vulnerable and the voiceless. And the timing couldn't be better, since this is a moment when we not only understand the depth of the mental health challenges facing young people, but have more tools than ever at our disposal to get them the help they need."