The Duchess of Cambridge has become the patron of four charities.
She has accepted honorary positions with Action on Addiction, East Anglia's Children's Hospices, the Art Room and the National Portrait Gallery.
Kate will also become a volunteer in the Scout Association, mostly working near her North Wales home.
St James's Palace said the choices reflected her interests in the arts, promotion of outdoor activity and supporting people in need of all ages.
"The duchess has chosen to support organisations that complement the charitable work already undertaken by her husband," it added.
Supporting charities is an important role for members of the Royal Family as they can help promote the profile of good causes on to the national stage.
The Art Room, which uses art therapy to help children with issues like low self-esteem and Asperger's syndrome at centres in Oxford and London, said it would make a great difference.
Founder and director Juli Beattie said: "We're absolutely delighted, we're overwhelmed and thrilled. "This is just fantastic, it will raise the profile of the charity and get people to see the work we are doing."
Kate is already patron of the charitable foundation William founded with his brother Prince Harry, but these are her first external patronages.
She will make private and public visits across the UK to her new organisations over the coming months.
Action on Addiction - which has its headquarters in Salisbury, Wiltshire, and helps people with a range of addictions at its treatment centres across England - welcomed her choice.
In November, Kate privately visited East Anglia's Children's Hospices (EACH) which provides care and support to children with life-threatening conditions and their families across Cambridgeshire, Essex, Norfolk and Suffolk.
There she met Grant and Charlotte Clemence whose daughter Fleur died soon after being born last May from a rare heart condition. The couple were supported by EACH in her final days.
Mr Clemence said: "The Duchess showed genuine interest to all the families and staff she met and it really will be a great boost for EACH."
The duchess has also accepted a role with London's National Portrait Gallery, which said it was looking forward to working with her.
The Duke and Duchess of Cambridge are living in north Wales, near to where William is based at RAF Valley on Anglesey.
Kate, who was a Brownie as a child, will volunteer with younger members of the Scout Association primarily at groups based around her home but also in other areas when opportunities arise.
UK chief scout Bear Grylls said: "The duchess has an incredibly busy life, which makes it all the more inspiring that she has chosen to volunteer alongside us."