Students with significant disabilities often attend general education (mainstream) classrooms, yet they are not receiving adequate support to experience full school participation. This qualitative case study was conducted to explore how key intrinsic (i.e. personal skills and abilities) and extrinsic (i.e. environmental) factors influence the participation of an elementary (primary) student with significant disabilities in an inclusive placement. Our goal was to promote a deeper understanding of meaningful participation that bridges the fields of occupational therapy and inclusive education. Using the Person-Environment-Occupation-Performance (PEOP) model as a theoretical framework and single-case design, data were collected from classroom observations and semi-structured interviews with the teacher, education assistant, and classmates of a third-grade student with physical and intellectual disabilities. Thematic analysis was deductive, guided by the theoretical framework. Findings suggest the expression of personal skills and abilities is dependent on extrinsic factors, such as the classroom culture and social environment. Findings also suggest a student with significant disabilities experiences minimal participation in occupations that foster academic inclusion. To promote meaningful participation in general education classrooms, we suggest addressing contextual factors that facilitate participation in occupations linked to the curriculum, thus supporting the need for collaborative partnerships between teachers and occupational therapists.