Large class sizes pose significant challenges in education, impacting the quality of teaching and learning. Many scholars have highlighted the consequences of large class sizes; however, few have focused on strategies to mitigate these effects to enhance the quality of teaching and learning. This study identified the key effects of large class size on teaching and learning in senior high schools in Ghana and explored effective pedagogical practices for improvement. A qualitative research method was employed, and purposive sampling was used to select 38 respondents. Primary data were gathered through focus group discussions and personal interviews. Key issues identified include difficulties in providing individualised attention, proper assessments, timely feedback, and effective classroom management, all of which hinder academic progress and contribute to poor student performance. To address these issues, the findings revealed that peer teaching and marking, group studies, recruiting more teachers to support collaborative teaching, field trips, and the use of projectors should be incorporated into teaching large class sizes. The study also emphasises the importance of professional development training for teachers to improve their methodologies and confidence in managing large classes. The study concludes that these methods reduce teacher workload and improve the overall teaching and learning experience. The study recommends that the Ghana Education Service should encourage teachers to employ these strategies in large classes to improve the quality of teaching and learning.