Upper respiratory tract infection (URTI) is considered to be the most common reason for children's visits to emergency departments or outpatient clinics. The misuse and overuse of antibiotics are currently major public health problems worldwide. This study aimed to assess Saudi parents' knowledge, attitude, and practice (KAP) regarding the use of antibiotics in URTIs in children. This cross-sectional study was conducted in Saudi Arabia using a previously validated questionnaire, which was distributed using Twitter. A total of 385 individuals completed the questionnaire. For the majority of the participants (77%), physicians were the primary source of information regarding the use of antibiotics. Forty-four percent of parents agreed that most URTIs are caused by viruses, and 81% were aware that inappropriate use of antibiotics leads to the development of antibiotic resistance. Fever was the primary symptom (27%) that led parents to ask for prescriptions for antibiotics. Although women had a higher attitude score (p=0.01), there was no difference between genders regarding knowledge and practice. Older participants (41 years or more) had a lower attitude score (p=0.02). Furthermore, participants with five children or more had lower attitude and practice scores (p=0.006, 0.04, respectively). Participants who lived in large cities had greater knowledge compared to the inhabitants of small cities (p=0.01). In conclusion, the findings of this study demonstrated that most of the participants were educated but lacked knowledge regarding antibiotic use in URTIs in children. This lack of knowledge led to inappropriate attitude and practice. Thus, launching public educational campaigns and encouraging physicians to educate parents regarding the proper use of antibiotics are recommended.