This research aimed to investigate the effect of teachers' motivational strategies and supportive behavior in virtual education on the academic performance of monolingual and bilingual students in English language courses. The research method was descriptive-correlational, and the statistical population included high school teachers and students in Ahvaz. Multi-stage stratified cluster sampling was performed, and data were collected from 96 teachers and 192 students (96 monolingual and 96 bilingual) using standardized questionnaires for motivational strategies (TUMSS) and supportive behavior (TUSBS). Data analysis was conducted using SPSS version 24, employing Pearson correlation coefficient, multiple regression, independent t-test, and Fisher's z-test. The findings showed that teachers' motivational strategies and supportive behavior have a positive and significant relationship with academic performance in both groups, but the strength of this relationship for supportive behavior was significantly stronger in the bilingual group (z = −2.04, p < 0.05). Additionally, the regression model indicated that in the bilingual group, both predictor variables significantly predicted performance (R² = 0.37), while in the monolingual group, only supportive behavior had a significant effect (R² = 0.16). These results suggest that in a virtual environment, teacher support for bilingual students acts not only as a facilitator but also as a compensatory factor against linguistic-cultural gaps. Furthermore, a significant difference was observed between teachers' and students' perceptions of the use of these strategies (p < 0.001), indicating the presence of self-report bias in teachers and the necessity of using multi-source assessment. Overall, the findings emphasize that the success of virtual education in multilingual regions, beyond technological infrastructure, depends on the quality of the human relationship with the teacher, especially through empathetic and responsive supportive behaviors.