The purpose of this study was to determine the relationship between English proficiency and Mathematics performance of the grade six students in cluster 3 Malabog District, Davao City. The researcher used the descriptive-correlation design to investigate the phenomenon. The respondents were selected from four schools under Malabog District, Davao City. They were selected using clustered sampling techniques. Mean, Pearson r and regression analysis were used in the analysis of data. Findings revealed that English proficiency of the grade six students were low. Moreover, the vocabulary, grammar and reading comprehension of the students, were at the beginning stage. Students’ mathematics performance was at the approaching proficiency stage. Furthermore, students’ vocabulary had a significant relationship on their mathematics performance. Nevertheless, students’ vocabulary best predicted their mathematics performance but it cannot stand alone. The contribution of the reading comprehension and grammar helped in the mathematics performance of the students.