This article sets out and critically analyses the state of current knowledge on Widening Participation at higher education institutions in Scotland and sets forth avenues for further research. Through a semi-systematic review of the literature, six discrete but overlapping themes relating to Widening Participation are identified, namely, (1) factors affecting the decision to apply to university, (2) the transition from high school or further education into university, (3) contextualised admissions, (4) completion and level of attainment, (5) economic, social and cultural capital and (6) equality, diversity and inclusion. The study finds that while clear progress has been made by higher education institutions towards achieving quantitative government targets for student recruitment from underrepresented groups, there is an absence of studies and knowledge about the qualitative lived experiences of students as they transition through university, how students negotiate a sense of fit with institutional systems, and what targeted supports they may require to succeed. Avenues for further research which addresses these gaps in the knowledge base are put forward, namely, (1) broaden the academic base and interdisciplinarity of Widening Participation research, (2) reform and extend measures of success beyond admissions and attainment, (3) evolve institutional level support for transition into higher education, (4) develop more nuanced understandings of contextualised admissions and (5) investigate and gain deeper understandings of how the lived experiences of Widening Participation students shape and inform their journey through, experience of and attainment at university.