The influence of fibre hybridization on the multifunctional performance of jute–banana fibre reinforced bio-epoxy composites was experimentally evaluated to assess their suitability for lightweight structural and acoustic applications. Alkali-treated jute and banana fibres were used as reinforcements, and composite laminates with different hybrid ratios were fabricated while maintaining a constant fibre loading of 40 wt.%. Mechanical, dynamic mechanical, acoustic, vibration damping, thermal, hygrothermal, and morphological characterizations were performed to evaluate the developed composites. The laminate reinforced with 100 wt.% jute fibre (J100) exhibited the highest tensile strength (72 ± 1.6 MPa), flexural strength (110 ± 3.2 MPa), and thermal degradation temperature (298 ± 3 °C), reflecting the superior stiffness and thermal stability of jute fibres. In contrast, the laminate reinforced with 100 wt.% banana fibre (B100) demonstrated the highest impact strength (41 ± 1.5 kJ/m 2 ), damping ratio (0.082 ± 0.003), and noise reduction coefficient (0.48 ± 0.03), indicating enhanced flexibility and energy dissipation. Fibre hybridization promoted improved stress redistribution and stronger fibre–matrix interactions, resulting in balanced structural and functional characteristics. SEM analysis further revealed improved fibre dispersion and reduced interfacial defects in the hybrid laminates. A comparative evaluation of tensile strength, damping ratio, water absorption, and glass transition temperature identified the JB50 laminate as the hybrid configuration exhibiting the most balanced multifunctional performance among the investigated compositions. The overall findings demonstrate that the developed jute–banana fibre reinforced bio-epoxy composites are promising sustainable materials for lightweight structural, acoustic, and vibration damping applications.