We investigated the impact of COVID-19 restrictions on the duration of untreated psychosis (DUP). First-episode psychosis admissions (n = 101) to the STEP Clinic in Connecticut showed DUP reduction (P = 0.0015) during the pandemic, with the median reducing from 208 days pre-pandemic to 56 days in the early pandemic period, and subsequently increasing to 154 days (P = 0.0281). Time from psychosis onset to antipsychotic prescription decreased significantly in the pandemic (P = 0.0183), with the median falling from 117 to 35 days. This cohort study demonstrates an association between greater pandemic restrictions and marked DUP reduction, and provides insights for future early detection efforts.