Despite the dramatic rise in Autism Spectrum Disorder (ASD) prevalence, limited information is known about ASD knowledge of the general population. The Autism Spectrum Knowledge Scale, General Population version (ASKSG) was collaboratively constructed to create a measure of ASD knowledge specifically for the general population. The ASKSG is a 31-item measure that assesses one’s knowledge and understanding of ASD. Adults in the general population participated in the current study (N = 318). Findings indicate that the ASKSG is a valid and reliable measure and can adequately measure ASD knowledge in this population. A greater understanding of general population knowledge pertaining to ASD can be used to better inform identification, intervention, and advocacy, thus improving the outcomes for individuals with ASD.