The Duchess of Cambridge will launch the pilot of a website aimed at giving primary school teachers practical resources to help support the mental health of their pupils.
Kate will give the green light to the initiative during a visit to a London primary school helping to trial the online portal coordinated and financed by the duchess' Royal Foundation.
The free website for schools, called Mentally Healthy Schools, is expected to be available to primary's nationwide in the spring after being monitored and reviewed.
Former head teacher, Claire Thomson, one of the website's quality assurance advisers, said: "I can see this website becoming a favourite go-to site for information about the many aspects of mental health.
"I think it is really important that all school staff feel that the information applies to them as well, not just to teachers. So, no matter what their role in the school, they need to have an understanding and empathy towards all the children."
The website will draw together reliable and practical resources to improve awareness, knowledge and confidence in promoting and supporting pupils' mental health.
The content will be provided in four main areas - teaching resources, risks and protective factors, mental health needs, and a whole school approach for school leaders.
The website aims to build on the Duke and Duchess of Cambridge and Prince Harry's Heads Together campaign, which last year encouraged people to speak about their mental health problems or provide a sympathetic ear for someone with issues.
William, Kate and Harry are each driving forward a series of programmes to ensure people can get access to the right help, at the right place and at the right time, with the duchess focusing on supporting young people.
The duchess brought together Heads Together charity partners, teaching organisations and mental health experts to create the online project.
The launch on Tuesday will take place at Roe Green Junior School, Kingsbury, north-west London, where Kate will meet teachers and pupils, and join a class taking part in one of the lesson plans featured on the site before giving a speech.