This report explores the largely unmeasured consequences of the COVID‑19 pandemic on early childhood development in the WHO European Region. It reviews disruptions to essential services such as health care, early learning, childcare, and family support, as well as increased stressors on caregivers and households. The analysis highlights significant data gaps and missed opportunities to monitor, protect, and prioritize young children’s development during crisis response and recovery. It calls for stronger systems, better data, and child‑centred policies to mitigate long‑term developmental and social impacts.