Catatonia is a neuropsychiatric disorder characterised by psychomotor changes that can affect individuals across the lifespan. Although features of catatonia have been described in adults, the most common clinical symptoms among paediatric patients with catatonia are not well characterised. The goal of this study was to characterise the symptoms of catatonia demonstrated by paediatric patients, and to explore demographic and diagnostic factors associated with greater catatonia severity. We conducted a multicentre retrospective cohort study, from 1 January 2018 to 6 January 2023, of patients aged 18 and younger with a clinical diagnosis of catatonia and symptom assessment using the Bush Francis Catatonia Rating Scale (BFCRS). A total of 143 patients met inclusion criteria. The median age was 15 (interquartile range: 13-16) years and 66 (46.2%) patients were female. Neurodevelopmental disabilities were present in 55 (38.5%) patients. Patients demonstrated a mean of 6.0 ± 2.1 signs of catatonia on the Bush Francis Catatonia Screening Item, with a mean BFCRS score of 15.0 ± 5.9. Among the 23 items of the BFCRS, six were present in >50% of patients (staring, mutism, immobility/stupor, withdrawal, posturing/catalepsy, rigidity), and four were present in <20% of cases (waxy flexibility, mitgehen, gegenhalten, grasp reflex). In an adjusted model, patients with neurodevelopmental disorders demonstrated greater BFCRS severity than those with other diagnoses. Catatonia was diagnosed in a range of mental health conditions. Further research is needed to define optimal diagnostic criteria for catatonia in paediatric patients, and clarify the clinical course of the disorder.