Globally, studies have shown that the dental disease burden among persons with intellectual and/or developmental disabilities (IDD) is high and can be attributed to lower utilization levels of dental services. The aim of the study was to assess the influence of income and financial subsidies on the utilization of dental care services among persons with IDD in Singapore. Between August 2020 and August 2021, a cross-sectional study was conducted via centres offering Early Intervention Programme for Infants and Children, special education schools and adult associations in Singapore serving persons with IDD. A sample of 591 caregivers of children and adults with IDD completed the survey. Data on sociodemographic information, oral health behaviours and dental utilization were collected. Financial subsidy status was assessed by the uptake of a government-funded, opt-in Community Health Assist Scheme (CHAS) for low-income families that provided a fixed subsidy amount for dental services in the primary care setting. Statistical analysis was carried out using univariable, multiple logistic regression and modified Poisson regression. Propensity score matching was carried out in R version 4.0.2 to assess the impact of financial subsidies on oral health care utilization among persons with IDD. Compared to those with lower gross monthly household incomes, the adjusted prevalence ratios of having at least one dental visit in the past year, having at least one preventive dental visit in the past year, and visiting the dentist at least once a year for persons with IDD with gross monthly household incomes of above SGD$4000 were 1.28 (95% CI 1.08-1.52), 1.48 (95% CI 1.14-1.92) and 1.36 (95% CI 1.09-1.70), respectively. Among those who were eligible for CHAS Blue subsidies (247 participants), 160 (62.0%) took up the CHAS Blue scheme and 96 (35.4%) visited the dentist at least yearly. There was no statistically significant difference in the utilization of dental services among individuals enrolled in the CHAS Blue subsidy scheme among those eligible for CHAS Blue subsidies. Higher household income was associated with a higher prevalence of dental visits in the past year, preventive dental visits in the past year, and at least yearly dental visits. CHAS Blue subsidies alone had limited impact on dental utilization among persons with IDD who were eligible for subsidies.