ObjectivesTo describe the impact of the COVID-19 pandemic on outpatient appointments for children and young people.SettingAll National Health Service (public) hospitals in England.ParticipantsAll people in England aged <25 years.Outcome measuresOutpatient department attendance numbers, rates and modes (face to face vs telephone) by age group, sex and socioeconomic deprivation.ResultsCompared with the average for January 2017 to December 2019, there was a 3.8 million appointment shortfall (23.5%) for the under-25 population in England between March 2020 and February 2021, despite a total rise in phone appointments of 2.6 million during that time. This was true for each age group, sex and deprivation fifth, but there were smaller decreases in face to face and total appointments for babies under 1 year. For all ages combined, around one in six first and one in four follow-up appointments were by phone in the most recent period. The proportion of appointments attended was high, at over 95% for telephone and over 90% for face-to-face appointments for all ages.ConclusionsCOVID-19 led to a dramatic fall in total outpatient appointments and a large rise in the proportion of those appointments conducted by telephone. The impact that this has had on patient outcomes is still unknown. The differential impact of COVID-19 on outpatient activity in different sociodemographic groups may also inform design of paediatric outpatient services in the post-COVID period.