Tourism has been a major economic pillar in numerous cities. A sustainable tourism development is vital while residents’ support is the lynchpin of success. The current study examines if and how support for sustainable tourism development is affected by place perception. Specifically, the mediating role of place attachment and moderating role of length of residency were examined. Drawn from a survey with 568 Macao residents, results show that place perception was a significantly positive contributor to residents’ support because of the higher place attachment. While length of residency strengthened the positive place perception—place attachment link, the place attachment—support link was not contingent on length of residency. The findings enrich the literature by examining the determinants of support for sustainable tourism development, the underlying mechanism, and the alternative role of length of residency. Useful implications for destination governors are discussed.