The present study aimed to investigate factors predicting inquiry-based teaching in science across One Belt One Road countries and regions (OBOR economies). Teacher-level (N = 8,603) and school-level (N = 1,385) data were drawn from the Program for International Student Assessment (PISA) 2015. Hierarchical linear modeling was adopted for data analysis. The results showed at the teacher level that teacher collaboration was positively correlated with inquiry-based teaching in OBOR economies, and that teacher beliefs were positively associated with inquiry-based teaching in each sample. At the school level, no consistent result was found among OBOR economies. School location was positively related to inquiry-based teaching in the Dominican Republic, Macao, and the United Arab Emirates. By contrast, science-specific resources showed a negative association with inquiry-based teaching in Taiwan, the Czech Republic, and Macao. Other specific findings were presented and the implications of all findings were discussed.