This study presents an experimental investigation into the shear strength of 3D-printed concrete (3DPC) beams subjected to three-point bending. The campaign focused on evaluating the influence of various parameters, including longitudinal reinforcement ratio, beam height, shear slenderness, as well as the effect of a deliberate pause during the printing process. To assess the specific behavior of 3DPC, a reference beam was traditionally cast for comparison. All specimens were reinforced longitudinally with carbon fiber reinforced polymer (CFRP) rebars. The primary objectives were twofold: to compare the structural performance of 3D-printed versus cast beams, and to examine the sensitivity of printed beams to variations in geometric, printing and mechanical parameters with regard to shear strength. Results highlight differences in bond behavior between printed and cast specimens, which in turn influence the failure mechanisms and overall shear capacity. Notably, a 15-min interruption in the printing process was found to not diminish beam capacity, but a 60-min gap did affect interlayer bonding, resulting in an altered crack pattern and earlier failure. The findings of this study contribute to the broader advancement of innovative construction methods by deepening the understanding of 3DPC’s structural behavior and its interaction with CFRP reinforcement. Ultimately, the results reinforce the potential of 3D printing as a viable technique for the development of resource-efficient, load-bearing concrete structures.