This is a multi-national mixed methods longitudinal research study involving partner universities from Canada, the United Kingdom, and Germany. This research aims to enhance the scholarly literature by building a grounded theory on improving international student engagement in higher education classrooms. It will also contribute to improving international student engagement and participation in the classroom, with a particular focus on fostering in-class communication among students from culturally diverse backgrounds. More specifically, the project aims to investigate the complex interplay between university belonging, social interactions, and engagement in collaborative learning among international student university beginners at both the undergraduate and graduate levels. Our team of ten educational researchers will delve into how these factors, including university support services, accommodation arrangements, and the university climate influence or moderate these processes. Further, based on examining effective case studies with as many as 50 students from each country, we will compile a repository of best practices and disseminate successful case studies of participation and intercultural collaboration in the classroom through various mediums (e.g., academic publications, website, conferences, institutional workshops) to support higher education instructors. By sharing best practices and facilitating knowledge exchange from the three countries, the project will contribute to creating a safe, inclusive, welcoming, and enriching learning experience for all students. It will also address the gap in the international literature on how the complex interplay between university belonging, social interactions, and engagement in collaborative learning among international student university beginners compares across differing cultural and national contexts and throughout the student lifecycle.