Kate, 41, was the surprise opening act of the annual charity fundraiser in a video message.
Wearing a favourite £175 blue blouse dotted with rainbows by London brand Lisou, she told the audience: ‘Hello everyone. I’m delighted that Children in Need have invited me to open this evening’s show.’
Her appearance was timely given her landmark speech earlier this week on the importance of early childhood and the affect that experiences between the ages of birth to five can have on adult life.
‘Tonight is all about helping to support, champion and empower all children to be the very best they can be, which is crucial for their future health and happiness,’ the mother-of-three explained.
‘Our relationships, surroundings and experiences during the earliest years lay the foundations that shape the rest of our lives.
‘And yet sadly, we know that for too many people, stressful and traumatic situations in early childhood can cause harm and it can take many years to overcome.’
She concluded: ‘It is vital, therefore, that we nurture every childhood and why the sorts of projects supported by Children in Need are so important.
‘They help the very youngest, most vulnerable members of our society feel safe, secure and loved in these important, formative years, so that they can enjoy their childhoods now, and grow to reach their potential and thrive in the world in later life.
‘I hope you enjoy this evening’s show and best of luck to all those taking part in challenges and the incredible fundraising effort.’
It is the first time that the future queen has taken part in a television fundraiser such as Children in Need, which is expected to raise in excess of £35 million this year.
On Wednesday the princess organised a symposium in London of experts in the early years from around the world as part of a ‘global listening exercise’ designed to emphasise why the first few years of childhood are so important in laying the foundations for happy and healthy adult lives.
In a speech Kate called for ‘action at every level’ to support the next generation, arguing that growing up in a nurturing environment was as important to childhood development as learning to read and write.
She explained that after spending several years speaking to those whose lives had reached crisis point, she realised that there was a common theme.
Many of those in prison rehabilitation programmes or addiction recovery centres, as well as those affected by homelessness or mental health issues, pointed to a lack of ‘safety, belonging and love’ in early childhood.
‘Somehow these deep-rooted needs aren’t always met by the societies we are creating, and the effects are evident all around us – with poor mental health, anxiety, depression, abuse and addiction all too common, ‘ she said.
The princess added that it wasn’t enough to ‘simply wish for a better world’ and that intervention in easily childhood provided a ‘golden opportunity’ for change.