This study employs the circular restricted three-body problem (CR3BP) as the dynamical framework, for the purpose of investigating low-thrust orbit dynamics in the Earth–Moon system. First, the effect of low thrust on some dynamical structures that exist in the CR3BP is analyzed. Low-thrust capture and escape dynamics in the proximity of the Moon is investigated for preliminary mission analysis. Then, low-thrust periodic orbits—with potential practical application—are detected. To do this, the theorem of mirror trajectories, proven 6 decades ago, is extended to low-thrust trajectories. This represents the theoretical premise for the definition and use of a numerical search methodology based on modified Poincaré maps. This approach leads to identifying several low-thrust periodic orbits in the Earth–Moon system that are infeasible if only unpowered paths are considered. Two possible applications of low-thrust periodic orbits are described: (a) cycling transfer trajectories that connect Earth and Moon continuously, and (b) non-Keplerian periodic paths about the Moon, with potential use as operational orbits for satellite constellations.