<p>The use of Computational Fluid Dynamics (CFD) to predict the acoustic signature of marine propellers operating in highly turbulent and non-uniform flow conditions has attracted considerable academic and industrial interest over the past decade. The negative effects of radiated noise from underwater maritime vessels and shipping activities on marine ecosystems and aquatic life are well recognized. This noise originates from various sources, most prominently propellers. This study aims to characterize the noise levels generated by marine vessels through high-fidelity numerical modeling of hydroacoustic phenomena. We employed Large Eddy Simulation (LES), the Schnerr–Sauer cavitation modeling approach, and the compressive volume-of-fluid (VOF) method to simulate cavitating flow over the propeller and predict the far-field radiated noise using the Ffowcs Williams-Hawkings (FW-H) hydroacoustic analogy. This study provides insights into the flow physics of noise generation due to wake structures—such as tip, root, trailing edge, and hub vortices—and cavitation patterns, including sheet, tip, and hub cavitation, over marine propellers operating upstream of a rudder. We characterized the instability of vortical structures in the wake of the marine propeller, including tip/hub vortex oscillation and instability, mutual-inductance instability (leapfrogging effect), elliptic instability, and primary and secondary wake grouping. Additionally, we examined sound levels related to propeller loading, cavitation development, periodic pulsating cavitation, and pressure fluctuations in both the near-field and far-field. Finally, the comparison between modeled and measured noise provided insights into the spectral contributions of propeller- and non-propeller-generated noise, helping to define the range of applicability for the assumption that propeller sources dominate overall noise emissions from the vessel.</p>