The COLMO (Quantum Collapse Models investigated with Particle, Nuclear, Atomic and Macro systems) workshop aims to advance the understanding of Quantum Collapse, by bringing together theoreticians and experimentalists working in the field. New realistic dissipative and non-Markovian collapse models are being developed, including gravity-related ones, to solve a major conundrum in quantum physics: identification of a physical mechanism for the collapse of the wave function. At the same time, experimentalists search for signatures of the proposed collapse models with various and very different physical systems. Searches of anomalous heating, or of spontaneous radiation are performed in atomic, nuclear, and mesoscopic/macroscopic systems from underground laboratories to (planned) space-based experiments. A collaborative discussion of the various experimental approaches towards an optimized search of collapse model signatures is timely. COLMO will bring together the communities working in quantum collapse with the aim to set up a synergetic effort towards progress in the field.