This study explores ways to enhance pre-service English teachers’ curriculum development competency through collaboration with in-service teachers. To this end, a course was designed to incorporate three key competencies of curriculum development (curriculum literacy, curriculum development competency, and curriculum evaluation competency) while adopting task-based language teaching and collaboration with inservice teachers as teaching methods. The designed course was implemented in a university for validation and revision. Ten pre-service English teachers participated in the course, where they developed English curricula in response to requests from three in-service middle school English teachers. A questionnaire survey conducted at the end of the semester with both pre-service and in-service teachers revealed that the proposed course model adequately worked to improve the three key competencies of English curriculum development among pre-service teachers. Further, collaboration with inservice teachers was found to enhance pre-service teachers’ responsibility and active engagement in curriculum development, while also providing practical assistance and creative teaching ideas to in-service teachers.