Background: Positive attitudes toward people with intellectual disability (PWID) are essential for full social inclusion. Two variables that may shape public attitudes toward PWID are "knowledge of intellectual disability" and "quality of contact" with individuals who have disabilities. Method: Participants were 455 undergraduate university students in Saudi Arabia (241 male [53%] and 214 female [47%]). The Mental Retardation Attitude Inventory--Revised (MRAI-R) was used to examine attitudes toward PWID; two other scales were adapted to measure knowledge of intellectual disability and quality of contact with PWID. Cronbach's Alpha for reliability, analysis of covariance (ANCOVA), and Pearson's correlation were used to analyze the data. Results: The combination of knowledge of intellectual disability and quality of contact with PWID showed significant influence on participants' attitudes toward PWID. Neither knowledge about intellectual disabilities nor quality of contact with PWID alone significantly predicted attitudes toward PWID. Conclusion: Having a relative with a disability was a significant covariate of participants' attitudes. For Saudi university students, having both high levels of knowledge about intellectual disability and quality contact with individuals with intellectual disabilities were associated with more positive attitudes toward PWID. In addition, having relative(s) with disability was associated with positive attitudes toward PWID.