AbstractThe permanent settlement of rural migrants can greatly influence the city size distribution. Although there have been multiple theories about rural–urban migration, the different effects of determinants on the settlement intention of rural–urban migrants across different-sized cities lack studies and remain unclear. Based on the 2016 National Floating Population Dynamic Monitoring Survey Data of China, this study investigated the factors determining rural migrants’ urban settlement intention and compared different-sized cities. It was found that the settlement intention of rural–urban migrants across different-sized cities showed a U-shaped curve, which was largest in supersized cities, followed by megacities, large cities, and Type-II small cities, and it was the smallest in medium-sized cities and Type-I small cities. After controlling the other determinants, the relationship between city size and settlement intention was also a U-shaped curve, which may be explained by the Rosen–Roback model. Moreover, although personal income and urban social insurance suggested similar effects on settlement intention across different-sized cities, the effects of educational attainment, the length of migration, occupation, marital status, housing conditions, and interprovincial migration on settlement intention differed significantly between different-sized cities. Based on these findings, it was suggested that the citizenization of rural migrants should be promoted through multiple kinds of policies including hukou reform, social insurance policy and housing policy, and different-sized cities adopt differentiated urbanization strategies, with a focus on small towns and within-provincial rural migrants.