The aims of the study were to present the prevalence of dental service utilization among adults (age between 18 and 65) in Chinese megacities and to examine the associations of health insurance and city of residence with dental visits. This study was a cross-sectional analysis of the 2019 New Era and Living Conditions in Megacities Survey data with a sample of 4835 participants aged 18–65 from 10 different megacities in China. The data including gross domestic product (GDP) per capita of each megacity obtained from the National Bureau of Statistics of China as a city-level characteristic. After adjusting sampling weights, approximately 24.28% of the participants had at least one dental visit per year. Findings from multilevel mixed-effects linear models showed that participants residing in megacities with higher GDP per capita (β = 0.07, p < 0.001) who had Urban Employee Basic Medical Insurance (β = 0.25, p < 0.001) or Urban Resident Basic Medical Insurance (β = 0.19, p < 0.01) had more frequent dental visits after adjusting demographic characteristics, socioeconomic status, health status, health behavior and attitude, and oral health indicators. Margins post-estimation model results demonstrated disparities in the predicted probability of having never visited a dentist by types of health insurance and city of residence. In conclusion, the prevalence of dental visits in China was found to be low. This study highlights socioeconomic inequalities in dental service utilization. There is a great need to develop more dental care programs and services and expand health insurance to cover dental care in China.