QD Day 2019 is a one-day workshop on all aspects of research into semiconductor quantum dots. Topics will include electrical transport, optical properties, spin physics, quantum devices, and synthesis. This will be the latest in a series of highly successful workshops previously held in Sheffield, Edinburgh, Cambridge, Imperial College, Nottingham, QinetiQ, and University College London. Our goals are to focus on recent scientific developments and to bring together groups working in this field. Past meetings have stimulated many new contacts and collaborations.