The use of online teaching has increased rapidly, especially since the start of the global pandemic of COVID-19. K-12 teachers in Saudi Arabia, like many teachers globally, found themselves with a new way of teaching because of the pandemic. Thus, this study examined the unified theory of acceptance and use of technology (UTAUT) in elementary school teachers' acceptance of online learning. We tested whether UTAUT's four key factors (performance expectancy; effort expectancy; social influence; and facilitating conditions) affect Saudi Arabian elementary school teachers' acceptance of using online learning. We found that performance expectancy, social influence, and facilitating conditions altogether predicted teachers' use of online learning as the analysis of the multiple regression outcome found that 60.2% of the variation was affected by these variables.