Autistic students often experience poor educational outcomes that have implications for later life, including unemployment, interactions with the criminal justice system, increased risk for substance abuse, and low socioeconomic status. Improving educational outcomes is critical for ensuring that autistic young people can reach their potential. To quantify differences in suspension rates between autistic and nonautistic students and to assess whether high-need education-based funding for autistic students is associated with reduced rates of school suspension. This national cohort study used linked health and education data from New Zealand's Integrated Data Infrastructure. Data were obtained for students aged 5 to 16 years from January 1 to December 31, 2018, and analyzed July 7, 2021, to January 1, 2022. A novel case identification method was used to identify autistic students. High-need education-based funding (Ongoing Resourcing Scheme [ORS]) obtained before 2019. Rates of suspension from school. Crude and adjusted analyses of the association between suspension rates and autism among the full population with adjustment made for sociodemographic characteristics (sex, age, ethnicity, deprivation, and urban or rural profile of residence) were conducted using complete-case, 2-level random intercept logistic multivariable regressions. To assess the association between ORS funding and suspension, analysis was restricted to autistic students. Of the 736 911 students in the study population, 9741 (1.3%) were identified as autistic (median [SD] age, 10 [3.2] years; 7710 [79.1%] boys), and 727 170 (98.7%) as nonautistic (median [SD] age, 10 [3.4] years; 369 777 [50.9%] boys). School suspension was experienced by 504 autistic students (5.2%) and 13 845 nonautistic students (1.9%). After adjustment for demographic characteristics, autistic students had significantly higher odds of suspension than their nonautistic peers (adjusted odds ratio, 2.81; 95% CI, 2.55-3.11). Of the 9741 autistic students, 2895 (29.7%) received high-need education-based (ORS) funding. Suspensions were experienced by 57 autistic students (2.0%) with high-need funding and 447 autistic students (6.5%) without high-need funding. After adjustment for demographic characteristics, co-occurring conditions, and level of disability support need, autistic students with high-need funding had significantly lower odds of suspension than autistic students without high-need funding (adjusted odds ratio, 0.29; 95% CI, 0.21-0.40). In this cohort study, the findings of disparities in suspension rates between autistic and nonautistic students underscore the challenges faced in providing inclusive education for all young people, regardless of disability status. This study found that high-need funding was associated with reduced suspension rates among autistic students, suggesting that if appropriate supports are afforded to autistic students, a more inclusive education can be provided.