Sense of belonging, or belongingness in academia, is an individual's personal conviction as to their acceptance as a valued member of an academic community. The importance of belongingness lies in correlations with motivation, persistence, mental health and well-being. Prior work has shown that belongingness can be lower in students who are minoritised due to their gender, race, nationality, socio-economic status, religion and/or disability. However, there is limited research on how a student's university entry route impacts their sense of belonging in Computer Science and Other Science disciplines. In Ireland's higher education system, university entry is primarily managed through the Central Applications Office (CAO) process, which predominantly serves students transitioning directly from secondary school to university. Additionally, alternative access routes are available for students from socio-economically disadvantaged backgrounds, those with disabilities, and mature students. At University College Dublin (UCD), entry is facilitated through both the traditional direct-entry school leaving route and combined access routes, each serving distinct student demographics. To investigate how these varying entry routes influence students' sense of belonging, we utilised a survey adapted from the validated 'Math Sense of Belonging Scale' to examine the belongingness of undergraduate Science students, including Computer Science students. We examined how the belongingness of students varies by university entry route, and how the belongingness of students in Computer Science varies by university entry route compared to Other Science students. Our results reveal a significant difference in belongingness between students entering university through the direct-entry school leaving route, compared to those who entered via combined access routes (e.g. university admissions schemes for school leavers from socio-economically disadvantaged backgrounds, with disabilities, and mature students). Specifically, within Computer Science, students entering university through the direct-entry school leaving route had significantly higher belongingness than combined access route students. These results provide insight that may help others improve the belongingness of undergraduate Computer Science students.