Abstract: (1) Background: Cancer cells release extracellular vesicles that are a rich target for biomarker discovery and provide a promising mechanism for liquid biopsy. SEC is an increasingly popular technique which has been rediscovered for the purposes of EV isolation and purification from diverse biofluids. (2) Methods: A review was undertaken to identify all papers which described size exclusion as their primary EV isolation method in cancer research. (3) Results: 37 papers were identified and discussed which showcases the breadth of applications that EVs can be utilised, from proteomics, to RNA, and through to functionality. A range of different methods are highlighted, with Sepharose-based techniques predominating. (4) Conclusions: EVs isolated using SEC are able to identify cancer cells, highlight active pathways in tumourigenesis, clinically distinguish cohorts and remain functionally active for further experiments.