BackgroundAutism Spectrum Disorder (ASD) presents important challenges in inclusive education, requiring teachers to have adequate knowledge, positive perceptions, confidence, and appropriate classroom support skills. Despite the growing emphasis on inclusive education in Saudi Arabia, gaps remain in teachers’ ASD-related knowledge, professional training, and preparedness for supporting students with ASD in inclusive school settings.ObjectiveThis study aimed to assess knowledge and perceptions toward students with ASD among general and special education teachers in Riyadh, Saudi Arabia, and to identify demographic and professional factors associated with each outcome.MethodsA cross-sectional study was conducted among 381 general and special education teachers from primary, intermediate, and secondary schools in Riyadh. Data were collected using a self-administered questionnaire comprising demographic and professional characteristics, 20 knowledge items, and 15 perception items rated on a five-point Likert scale. Higher knowledge scores indicated greater factual knowledge of ASD, while higher perception scores indicated more positive perceptions toward students with ASD and inclusive education. Descriptive statistics were used to summarize participants’ characteristics and outcome scores. Pearson's correlation analysis examined relationships between continuous variables. Multiple linear regression analyses were conducted separately to identify predictors of knowledge scores and perception scores.ResultsMost teachers demonstrated moderate knowledge of ASD (53.0%), while 34.9% had good knowledge and 12.1% had poor knowledge. Teachers showed strong recognition of ASD as a neurodevelopmental condition and of the benefits of early intervention, although relative gaps were observed in areas related to instructional strategies, augmentative and alternative communication, and classroom support approaches. Perceptions were mainly neutral (43.8%) or positive (42.0%), indicating that many teachers supported inclusion but may still require additional confidence, resources, and professional support. Professional training, ASD teaching experience, and teaching role were important factors associated with teachers’ knowledge and perceptions.ConclusionGeneral and special education teachers in Riyadh demonstrated mainly moderate knowledge and neutral-to-positive perceptions toward students with ASD. The findings highlight the importance of structured ASD-focused professional development, practical classroom exposure, and collaboration between general and special education teachers to strengthen inclusive education practices in Saudi Arabia.