This present study centers sensitively on the determination of the effect of natural turkey feather fibers (TFFs) loading on fundamental features (thermal, mechanical, water-uptake, and micro-structural) of thermoplastic polyurethane (TPU). The composites with different TFFs contents (3, 6, 9, and 12 wt.%) were fabricated by the melt blending method using the twin screw extruder and micro-injection molder. The samples were characterized by means of differential scanning calorimeter (DSC), universal mechanical (tensile and hardness) tester, water-uptake, and scanning electron microscope (SEM) techniques. The thermal analysis depicted that the melting temperatures of the soft and hard segments as well as the crystallinity degree of TPU increased consistently with the increase of TFFs loading level thanks to the formation of better close-packed TPU chains in the matrices. As for the mechanical test results, when compared neat TPU, the tensile strengths were reinforced by 26.8% and 19.7%, and the modulus increased by 6.6% and 45.1% for the composite samples including 3% and 6% of TFFs, respectively. However, drastic diminishment were observed at further contents. Additionally, TFFs loadings brought about gradual increase in the water-uptake capacities of the composites due to the increasing of the number of voids and omnipresent flaws in TPU matrices. The taken SEM images also revealed that, at low contents, there existed the enrichment of interfacial adhesion between TFFs and TPU matrix, whereas the morphological appearance of the composites get worse at high contents accompanied by the formation of micro-structural defects.