Background: Coronavirus illness (COVID-19) has spread globally and is affecting everyone severely. The evaluation of educational needs (knowledge, attitudes, and practices) is important in controlling COVID-19 situations. The goal of this study is to find out what adults in Ardabil City know, how they feel, and what they do about the COVID-19 infection. Methods: In November 2021, a cross-sectional descriptive-correlational survey of 384 people was conducted using stratified-cluster sampling in Ardabil. The researchers created a self-reported questionnaire with 23 items as the data collection technique. The quantitative data were evaluated using descriptive statistics, the chi-square test, the correlation coefficient, and regression analysis. Results: The correct answer rate for this research found that 73.17% of participants ( n = 281) had appropriate knowledge, 61.19% ( n = 235) had favorable attitudes, and 69.53% ( n = 267) had enough practice behavior. However, knowledge was related to gender, employment, and location of residence. Age, marital status, education level, and location of residence were all connected with attitude. Age, gender, and marital status were all related to the behavior. The findings of linear regression analysis revealed that knowledge and attitude influence behavior. Conclusion: The study findings revealed a high degree of understanding of COVID-19, a positive attitude, and a strong commitment to good practices. Knowledge, attitudes, and behaviors were influenced to varying degrees by age, marital status, education level, employment, and location of residence. Furthermore, knowledge and attitudes influenced behaviors.