In May of 2022, the Basic Research Office of the U.S. Department of Defense and the Defense Science and Technology Group of Australia jointly sponsored the Future Directions Workshop on Quantum Information Science (QIS). In attendance at the workshop were U.S. and Australian scientists selected from a wide range of QIS disciplines as well as a group of government observers from both countries. The workshop was organized as two days of discussions that culminated in a set of proposed “grand challenges” that could foster collaboration between the two countries in this critical scientific area. Participants identified opportunities for collaboration within quantum sensing, computing and communication. The topics considered spanned length scales from the atomic to the continental, incorporating workforce and infrastructure components that could both contribute to the scientific progress of both nations and support economic development of new technologies. This report documents the wide-ranging discussions that occurred throughout the meeting and provides an overview of the grand challenges and opportunities for collaboration that the participants identified, as well as discussion of the context in which the meeting was held, including recent advancements in QIS research and development.