This study explored how teachers have adapted the Montessori method in Saudi early childhood classrooms to align with Saudi socio-culture and Islamic practices. The study was framed using the socio-cultural theory. A qualitative multi-case study design was used to collect data from semi-structured interviews and on-site observations for four Saudi early childhood teachers in two Montessori classrooms in Saudi Arabia. The data were thematically analyzed manually and with NVivo software. The study results showed that the teachers encouraged children’s independence and freedom of choice in work time and during the classroom day, but limited their freedom during mini-lessons and circle times to meet religious or cultural expectations. The results also highlighted that the flexibility of the school culture and the Montessori method encouraged the teachers to cooperate in designing lessons and activities for the Saudi Montessori classroom context. The study found that the teachers integrated the Islamic and Saudi socio-cultural practices most in circle time, classroom activities, and the daily classroom routine to teach academic, social, and behavioral practices. The results also highlighted that the Montessori system and school rules encouraged organizing the classroom environment. The socio-cultural theory illuminated how the teachers’ adaptations of Montessori principles and Islamic and Saudi socio-cultural practices were affected by their background, beliefs, and experiences. Implications of the study were discussed and recommendations given for early childhood teachers, the Saudi Ministry of Education, and higher education programs. Further research could focus on comparative analysis between teachers implementing Montessori in Saudi Arabia and in a Western country to highlight the cultural influences on adapting the Montessori approach