In recent years, the implementation of smart city projects has accelerated around the world, including in Japan. One of the potential challenges of the implementation is the issue of social acceptance. As a factor closely related to the social acceptance of smart city projects, we focus on trust in business operators. This study examines the relationship between trust in business operators and (1) perceptions of shared value (i.e., perceptions that self and business operators pursue the same value), (2) perceptions of others’ attitudes (i.e., perceptions of what attitudes other citizens have toward the project), (3) perceived sincerity, (4) perceived competence, (5) perceived future potential, and (6) perceptions of the amount of personal information (i.e., perceptions of the extent to which personal information is obtained). In this study, an online survey was conducted in which participants (N = 9,320) read one of the four vignettes about smart city projects and responded to the items listed above. The vignettes were related to either personal credit assessment, garbage collection, human flow measurement, and countermeasures against COVID-19. The structural equation modeling showed that (1) those with a higher degree of perceptions of shared value and others’ attitudes had higher perceived sincerity and competence, (2) those with higher perceived competence had higher perceived future potential, (3) those with a higher degree of perceived sincerity, future potential, and others’ attitudes had higher trust in business operators, and (4) those with lower perceptions of the amount of personal information had higher trust. Similar results were obtained for the four vignettes. This study is a vignette-based survey, which has the major limitation of lacking reality. In the future, it is important to conduct a survey targeting residents of cities where smart city projects are actually implemented. We should consider a model similar to this study with respect to a wide range of smart city projects.