Greenspace (defined here as canopy coverage) positively correlates with improved well-being in typically developing individuals, but this relationship has not been established in children with autism spectrum disorder (ASD). To investigate this relationship, the current study merged data from the National Survey of Children’s Health (2012) with the National Land Cover Database. Across typically developing children, children with ASD, and non-autistic children with special healthcare needs (CSHCN), greenspace unexpectedly negatively correlated with well-being. Further, compared with typically developing children, children with ASD or CSHCN status had lower well-being. Interestingly, typically developing children with conduct problems displayed an unexpected negative relationship (i.e. as greenspace increased whereas well-being decreased), though those without conduct problems showed no relationship. Children with ASD displayed no relationship between greenspace independent of conduct problems. CSHCN displayed non-significant trends suggesting mild positive relationships between greenspace and well-being. These data indicate the relationship between greenspace and well-being is more complex than expected and may depend on the diagnostic traits of the population studied.