Precise and accurate theoretical predictions of the properties and dynamics of dense quantum many-body systems, such as in the early universe and in the interior of neutron stars, require exponentially large classical computational resources (with system size), and lie beyond the exascale computing era. As highlighted by Feynman and others, such systems may be amenable to quantum computation, requiring polynomial-scaling quantum resources only. The impact of quantum computing (QC) and quantum information science (QIS) on addressing Grand Challenge problems in Nuclear and High-Energy Physics will be discussed.  While the application of QIS and QC to the domain sciences is at its earliest stages, illustrative examples of recent calculations that I have been involved in, through collaborations with Oak Ridge National Laboratory and with colleagues in Seattle, will be presented.