Effective teachers are irreplaceable inhelping students succeed. They facilitate two-way teachingand learning processes, helping students learn contentthrough real time responses to questions, making learningfun, shaping students' attitudes, exemplifying empathy,modeling teamwork and respect, and building studentresilience in several ways. Successful teachers work withschool management teams and parents to ensure consistentsupport for students as they transition through school. Thesudden closure of schools during COVID-19 has left manyteachers across several countries uncertain about theirrole, unable to use technology effectively to communicateand teach, and unprepared for classroom challenges whenschools reopen. The pandemic has brought the need to bridgedigital divides into sharp focus, with countries and schoolsadept at using such technologies facing fewer challenges inmeeting learning goals. There can be little doubt thathigh-quality education is a social experience, requiringroutine human interface. Successful teachers areirreplaceable in this task—and will remain so in theforeseeable future—but they need to be supported in multipleways to be effective in unpredictable circumstances. Giventhe central role teachers play in student learning, thisnote outlines three key principles to help governments andtheir development partners in supporting teachereffectiveness during and in the aftermath of COVID-19. Itdiscusses these principles in relation to the three phasesof the World Bank’s COVID-19 education policy response:coping, managing continuity, and improvement andacceleration.1 The three principles are basic and applyregardless of country context.