Natural fiber-reinforced composites improve environmental sustainability, and their use is increasing as environmental awareness grows. Natural fibers, such as hemp and flax, are renewable resources. They offer several advantages, including abundant availability, low cost, and high biodegradability. Three-dimensional printing has introduced a novel approach for advancing natural fiber-based composites. However, there is a significant lack of research on the 3D printing of continuous hemp and flax fiber-reinforced thermoset composites. This research investigates the fabrication of hemp and flax fiber-reinforced thermoset composites using a UV-light-assisted 3D printing process. Both printed composites achieved a fiber volume fraction of approximately 13%. The tensile strength of hemp and flax fiber-reinforced composites was found to be 32.3 ± 3.5 MPa and 61.1 ± 4.2 MPa, respectively. Moreover, the flexural strengths of hemp and flax fiber-reinforced composites were 81.8 ± 13.5 MPa and 85.3 ± 23.1 MPa, respectively. Thus, this study may open research pathways for utilizing natural fiber-reinforced thermoset composites with improved biodegradability and renewability.