Students' sociolinguistic variations can pose several challenges in the language classrooms. The present study aims to explore and investigate the strategies to overcomes challenges of teachers’ bias in assessment grading based on students’ sociolinguistic variations. To this end, a mixed-method design was administered. First, a qualitative phase based on focus group interviews was administered with three groups of eight Iranian EFL teachers. Each group involved EFL teachers from three different contexts, namely universities, institutes, and schools. Furthermore, purposeful sampling was conducted in order to choose teachers who had frequently encountered this issue. A 70-minute online discussion was held with each group to examine what types of strategies they employed to prevent bias in assessment grading. The results of thematic analysis indicated that teachers’ strategies and solutions fell into four broad categories of bias awareness and reflection, inclusive and individualized approaches, collaborative and student-centered assessment, and clear and transparent assessment practices. Following this, a ranking scale was used to determine how these categories were ranked based on teachers’ beliefs. This study offers implications to English teachers, policy makers, and educational assessment system. It promotes fairness and equity by ensuring that students are evaluated based on language proficiency rather than sociolinguistic factors, enhancing the validity and reliability of assessments. This research supports linguistic diversity, informs teacher professional development, empowers students, and contributes to educational policy and practice, fostering inclusive and equitable language education practices.