The 2020-21 National Teacher and Principal Survey (NTPS) is a nationally representative survey of public and private K-12 schools, principals, and teachers in the 50 states and the District of Columbia. State-level data are also available for public schools, principals, and teachers. NTPS collects data on core topics including teacher and principal preparation, classes taught, school characteristics, and demographics of the teacher and principal labor forces. The survey is developed by the National Center for Education Statistics (NCES) of the Institute of Education Sciences (IES) within the U.S. Department of Education, and data are collected by the U.S. Census Bureau. This report presents basic estimates from the Public and Private School Data Files of the 2020-21 NTPS, the third collection of NTPS. The purpose of NTPS is to collect data to provide a detailed picture of U.S. elementary and secondary schools and their staff. Items about how schools first adapted to the coronavirus (COVID-19) pandemic during the spring of 2020 were included in the School, Principal, and Teacher Questionnaires. In addition, an item was included at the beginning of each questionnaire asking about the current effect of COVID-19 on instruction at the school at the time the survey was completed during the 2020-21 school year. This First Look report provides descriptive statistics and basic information from the 2020-21 National Teacher and Principal Survey Public School and Private School Data files. [For the Summary report, see ED624615.]