This book constitutes refereed proceedings of the 27th International Workshop on Frontiers of Computer Vision, IW-FCV 2021, held in Daegu, South Korea, in February 2021. The 17 full papers and 8 short papers presented were thoroughly reviewed and selected from 44 submissions. The papers in the volume are organized according to the following topics: real-world applications; segmentation / object tracking; recognition; human behaviour; algorithm / application.