Artemisinin-based combination therapies (ACTs) are the main treatment for falciparum malaria in Africa. Artemisinin partial resistance (ART-R), characterized by delayed parasite clearance after treatment, has been confirmed in four sub-Saharan African countries. In Ethiopia, molecular surveys have detected the Pfkelch13 R622I mutation associated with ART-R at multiple sites, but no study has yet combined clinical, molecular, and in vitro evidence to confirm ART-R per WHO criteria. This multisite study conducted across five sentinel sites in Ethiopia (2024-2025) assessed day-3 parasite positivity after artemether-lumefantrine treatment, Pfkelch13 genotyping, and ring-stage survival assay on culture-adapted field isolates, to determine whether ART-R is confirmed in Ethiopian Plasmodium falciparum populations.