Several studies reported the effectiveness of flipped classroom in facilitating learning and improving students' learning experiences, but few have focused on language learning (Arabic in particular). This research aimed to explore the effectiveness of the flipped classroom strategy in developing female 11th graders' Arabic grammatical competences in Arabic. A pre-test--post-test quasi-experimental design and a questionnaire were utilized to achieve such a purpose, using two equal groups (N = 100). The experimental group received the flipped classroom-based treatment, whereas the control group was taught with the usual method of teaching. Statistical methods (i.e. ANCOVA, t-test, and Pearson correlation coefficient) were used to analyze the data. The analysis revealed statistically significant differences between the mean scores of the post-test of the two groups in favor of the experimental group and a large effect size (F = 0.35). The study recommended using the flipped classroom strategy in developing the grammatical competence of native Arabic speakers, with all necessary technologies and infrastructure provided for schools.