The increasing number cases of coronavirus disease (COVID-19) infections in the general population in Indonesia raises questions concerning the public's knowledge and attitudes regarding this pandemic. To determine the correlation between the general public's knowledge and attitudes regarding the COVID-19 outbreak 1 month after the first cases were reported in Indonesia. This cross-sectional study was conducted between early March and the end of April 2020 in the general population of Indonesia, beginning with the North Sumatra region, where the spread of COVID-19 in Indonesia began. Questionnaires were randomly distributed online in the red zone in Indonesia. Data were collected by collecting people's responses to the questionnaire, which were distributed via WhatsApp (WA) application and were competed independently by the participants. A descriptive analysis was conducted to describe the demographic characteristics, knowledge, and attitudes of the general population. A total of 201 people had good knowledge (98%) and a positive attitude (96%) regarding the COVID-19 pandemic. The respondents had a negative attitude in relation to two aspects of the COVID-19 outbreak: having to always maintain a distance of 1.5 m when in crowds, and not being able to regularly exercise or eat nutritious food (78.6% and 79.1%, respectively). Most people in Indonesia have good knowledge and a positive attitude regarding the COVID-19 pandemic. However, negative attitudes were still found in this study, and as a result, transmission prevention measures cannot reach their maximum effectiveness by simply publicizing the increase in day-to-day cases to the general public.