The set of known and suspected ocean worlds continues to expand, leading to intense interest in their viability as potential habitats that may be or may have been inhabited. Previous missions such as Cassini-Huygens, Galileo and New Horizons provide a major incentive for future exploration of the icy Galilean satellites with Europa Clipper and JUICE. Understanding ocean worlds and preparing for their exploration requires input from a variety of scientific disciplines: planetary geology and geophysics (including active processes, e.g. plumes), atmospheric physics, life sciences, magnetospheric environment, space weathering, as well as supporting laboratory studies, preparatory studies for future missions and technology developments in instrumentation and engineering. We welcome abstracts that span the full breadth of disciplines that apply to the icy moons in the outer Solar System with potential liquid oceans underneath, and their exploration.