Recent breakthroughs in quantum computing hardware have created an explosion of research and activity in quantum information science. The rise of “Noisy Intermediate Scale Quantum” (NISQ) devices has revealed major algorithmic and architectural challenges within this new technology. For example, the potential roles of quantum and/or quantum-classical hybrid data structures on algorithm design and performance evaluation are subjects of intense research. The goal of the QCASA workshop is to showcase the novel studies and foremost applications of non-fault-tolerant quantum computers, and provide a timely forum for computational scientists, software developers, computer scientists, physicists and quantum hardware specialists to exchange and discuss ideas on current problems in quantum information science. The contributions in this workshop will help elucidate practical, near-term limitations of current quantum devices, gauge the effectiveness of a class of approximate circuits quantitatively, and garner insight on what degree of that approximation is optimal for a given regime of machine performance.