Economic resilience is one of the fundamental components of sustainable development and reflects the ability of regions to cope with shocks, adapt to changes, and return to desirable conditions. In this regard, urbanization can affect the economic resilience of provinces through the concentration of economic activities, infrastructure development, increased access to services, and the expansion of employment opportunities; however, the magnitude of this effect may differ across different levels of resilience. The present study aims to examine the effect of urbanization on the economic resilience of Iranian provinces and identify the heterogeneity of this relationship. To this end, data for 31 Iranian provinces over the period 1390–1403 were collected and analyzed using quantile regression. The results showed that urbanization has a positive and statistically significant effect at all levels of resilience, but the magnitude of this effect decreases as the level of resilience increases, with its coefficient declining from 0.173 at the 0.10 quantile to 0.150 at the 0.90 quantile. Per capita income also exhibits a weaker effect as the level of resilience increases; in contrast, the effects of human capital, investment, economic diversification, and government expenditure become stronger at higher quantiles. The Wald test also confirmed statistically significant differences in the coefficients across quantiles. Therefore, policies to enhance resilience should be designed according to the resilience level of each province, emphasizing planned urbanization and higher per capita income in provinces with lower resilience, and strengthening human capital, investment, economic diversification, and improving the composition and efficiency of government expenditure in provinces with higher resilience.