Mrs Archer said more than 20 not-for-profit agencies will be supporting the event and there will be opportunity for parents and caregivers to learn about the organisations.
This will be the 10th year that Children's Day has been held in Whanganui and Mrs Archer said the number of agencies involved and the numbers of people attending has grown steadily each year.
Children's Day is celebrated on various dates around the world and was first proclaimed by the World Conference for the Well-being of Children in 1925 and then established universally in 1954.
The celebration at Springvale Park on Sunday is from 11am until 2pm and all the events are free.