The need to improve school instruction quality has led the education stakeholders to discover practical approaches to achieving that goal. This research aimed at establishing the impact of single-sex classrooms on K-12 female academic achievement. The objectives include establishing the perceptions of teachers on how single-sex female classrooms affect the experiences of K-12 female students; and how these perceptions can be used to develop initiatives that improve the experiences of K-12 female students in single-sex classrooms. The study explored past literature under different sub-topics to enlighten about the topic and the issues leading to single-sex classrooms for girls. It utilized qualitative data to help gather in-depth data and also obtain new ideas about the research problem. A sample of 10 educators who worked with girls in single-sex schools were used where email interviews were utilized to ask structured interview questions. The data was then analyzed using thematic analysis. The study established that a single-sex classroom improves understanding of course contents, enables a good learning environment, and improves positive enjoyment of learning experiences. However, the same learning environment was associated with learner dissatisfaction, inability to integrate with other learners, and imbalance in experiences of learners. The single-sex classroom was also seen to enable the development of initiatives that improve the experiences of K-12 females. This study gave educators with experience a chance to express their perceptions of single-sex classrooms. Given the findings, single-sex classrooms are beneficial to female students in helping them cope, learn concepts, and enjoy learning experiences. A review of adverse opinions that sufficed, such as learner dissatisfaction, recommended further research exploring the perceptions, experiences, and attitudes of students in single-sex classrooms in conjunction with teachers' perspectives. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]