A school psychologist works within education, assessing and supporting children whose learning, behaviour or emotional wellbeing is getting in the way of their progress at school. The work covers cognitive and learning assessment where a difficulty is suspected, advice to schools on classroom support and reasonable adjustments, and contributions to the formal plans that set out what extra support a child is entitled to.
A title that means different things in different places
School psychologist is the term used in the United States and in several other countries, and it is worth knowing that the title does not map directly onto a UK role. In the UK, the equivalent work is done by an educational psychologist, a title protected by law and requiring registration with the Health and Care Professions Council, unlike some of the more loosely used titles elsewhere in this field.
Working with the adults around a child
A meaningful part of this work happens through consultation with teachers and parents rather than directly with the child alone, since changes to how a classroom or a home responds to a difficulty often make more difference than time spent one to one. If you are looking for this kind of support for a child in the UK, searching for an educational psychologist rather than a school psychologist will get you closer to the right professional.