Background: Despite recent government efforts to control antibiotic purchase by the public, the rate of self-prescription is still alarmingly high in Saudi Arabia. Increased and inappropriate antibiotic use has been identified as an important factor behind bacterial resistance. Recently, there has been an increased interest in the Saudi public’s awareness of antibiotic use and resistance. However, none of the local studies examined the awareness and practices among patients attending primary care services. Additionally, the influencing factors of awareness and practices have never been comprehensively examined. Objective: To assess the levels of knowledge, attitude, and practices of antibiotic use and their influencing factors among a sample of patients at a primary care setting. Methods: A cross-sectional design was used to examine patients attending Al Wazarat Health Center in Riyadh between 1 January 2018 and 31 March 2018. Data was collected using a structured study questionnaire which included data on socio-demographic and clinical characteristics of the participants, as well as knowledge, attitude, and practices of antibiotic use. Scores were calculated for knowledge, attitude, and practices of antibiotic use and were translated to a 100-point scale for easy interpretation. Results: The current analysis included 343 participants. The average age was 32.5 ± 10.0 years. The majority of the participants were women (63.0%), married (65.9%), and had college or higher education (57.0%). The overall antibiotic awareness level was 54.7% (including 43.9% for knowledge and 71.7% for attitude) and appropriate antibiotic practices were 68.3%. The scores of both awareness and practices were positively and significantly correlated (correlation coefficient = 0.440, P < 0.001). In addition to appropriate antibiotic practices, awareness was significantly associated with higher educational level and having children. Conclusions: The current findings indicate the need to improve awareness and understanding of the public regarding appropriate antibiotic use by targeting patients who attend primary care services with posters, structured educational sessions, and physician advice.