Recently developed natural fiber-reinforced polymer composites have a number of societal, economic, and environmental benefits for many technical uses. The objective of this study was to analyse the mechanical, combustible, and water absorption characteristics of ternary mixes with different ratios of natural bamboo fibre (35wt ) and zinc oxide (ZnO 0-3, 6, 9, 12, and 15wt ). Polylactic acid (PLA) composites made from bamboo fibre may have reduced total heat release (THR), total smoke emission (TSE), and heat release rate (HRR)using cone calorimetry study. The heat release rate was cut in half, from 262 kW/m² to 173 kW/m², by using 15wtnanoZinc oxide. The mechanical properties of the composites improved as nanoZinc oxide was added; at 15wtnanoZinc oxide, the flexural (54.63 MPa) and tensile (47.59 MPa) strengths of the materials achieved their maximum values. The PLA composites made from bamboo fibre showed uniform dispersion of n-ZnO when the n-ZnO content increased from 3 to 15wt. After n-ZnO particle integration, the X-ray diffraction (XRD) showed no discernible peak, indicating that the granules were of uniform composition. When comparing pure PLA, PLA with Bamboo fibre, and hybrids with 3, 6, 9, 12, and 15 wt of ZnO filler, the greatest water absorption in hybrids is reduced by 14.56, 16.73, 21.45, 24.77, and 20.69 , respectively. In order to boost stiffness and decrease moisture absorption, hybrid composites made from natural bamboo fibre utilized nanoZnO particles as barriers. These findings suggest that such components might be suitable for applications in the nautical, outdoor, and packaging industries, where exposure to moisture is commonplace. These results also indicate that these composites might be used in settings where fire safety is of paramount importance. © 2025 Elsevier B.V., All rights reserved.