The present study examines the impact of incorporating graphene nanoparticles on the mechanical, vibrational, and moisture resistance properties of hybrid composites (HC) reinforced with ramie/abaca fibres. The composites were produced using compression moulding, with graphene dispersed in distinct concentrations (0.5, 1.0, and 1.5 wt%) in the epoxy matrix through ultrasonic sonication. The sample with 1.5 wt% graphene exhibited the highest performance, attaining a tensile strength (TS) of 22 MPa and a modulus of 3,116.897 MPa, representing increases of 175 % and 93.77 %, respectively, over the neat composites. The flexural strength also reached 70.64 MPa, showing a 139.29 % improvement. Increasing the graphene content to 1.0 wt% (RA1.0) resulted in an impact strength of 4.69 J, a 94.60 % improvement over the neat composite. Atomic force microscopy (AFM) and Field emission scanning electron microscopy (FESEM) were used to examine the microstructure of HC. In free vibration analysis, the composite with 1.5 wt% graphene recorded the highest natural frequencies, indicating greater stiffness and less energy dissipation. The Shore D hardness increased with graphene content, reaching a peak of 82.2 at 1.5 wt% graphene inclusion. Water absorption reduced from 14.1 % in the unmodified composite to 10.8 % with 1.5 wt% graphene, demonstrating enhanced moisture resistance. Integrating 1.5 wt% graphene significantly improves the mechanical strength, stiffness, surface hardness, and moisture resistance of ramie/abaca HC, making it suitable for weight-sensitive applications in automotive, marine, and aerospace sectors.