In recent years, the popularity of online food delivery (OFD) services has been increasing, potentially affecting eating-out travel patterns. This study, based on four theoretical hypotheses — substitution, complementarity, modification, and neutrality — uses a stated preference approach to assess the impact of OFD services on the frequency of eating-out trips and the choice of travel modes (car, public transit, bicycle, and walking) among 543 respondents in Chengdu, China. A multinomial logistic regression and four binary logistic regressions were constructed to further explore the influential factors. The analysis reveals that OFD services tend to substitute all modes of transportation, with a more pronounced effect on sustainable travel modes (walking, bicycling, and public transit) compared to driving. Specifically, frequent OFD users, those who find OFD services convenient, and individuals who prefer cycling are more likely to reduce their eating-out trips. The study concludes by discussing the implications for the restaurant industry and transportation system.