The transition to school is a critical period for children and families. Successful transition predicts later school achievement and socio-emotional outcomes with sustained long-term benefits. Educational disruptions caused by the COVID-19 pandemic meant that support for the transition of children from nursery to school was limited. The study aimed to investigate the impact of the pandemic on early years transitions in the U.K., with a focus on children with Special Educational Needs and Disabilities. Using a sequential mixed-methods research design, data was gathered from a survey before children started school, and semi-structured interviews after starting school. Results revealed that support for the transition of young children from nursery to school was inevitably affected. Key challenges and facilitating factors in planning for transition are reported as well as the impact of the pandemic on children, families and early years practitioners. The paper concludes with recommendations for policy and practice.