This study analyzed the spread of COVID-19 countermeasures by offices of education in terms of isomorphism. To this end, a total of 3,150 press releases and briefing materials from the Seoul and six other metropolitan offices of education were analyzed in five research stages, and the results were presented in four categories. Each office of education introduced measures related to school quarantine and distance education relatively early on to cope with COVID-19, and later presented measures related to welfare and psychology and health. Examples of countermeasures featuring isomorphism were support groups related to school opening that started in Daejeon (March 16, 2020) and packages that first began in Busan (March 3, 2020). As with these examples, countermeasures that were started in one region spread to other regions with considerable similarity. On the basis of the findings, the causes of isomorphism among the education offices are discussed. First, the uncertain situation of COVID-19 contributed to the spread of similar countermeasures. Second, the disaster status of COVID-19 made the offices of education strategically use other offices’ countermeasures in order to respond rapidly. Based on the results, it is suggested that a study to identify factors and mechanisms creating isomorphism among the offices of education that incorporates the various sources related to the response to COVID-19 is needed.