Natural fiber reinforced green composites have been attracting high attention nowadays, as the green movement in the world forced companies to use green materials instead of synthetic fibre reinforced composites. In this respect, the aim of the study is to investigate usage possibility of undervalued Chrysanthemum morifolium stem fibers as a new reinforcement of composite materials. Chemical, thermal, crystallographic, density, mechanical and morphological characterizations of the C. morifolium fibers were examined. Crystallinity Index, density and tensile strength values were found as 65.18%, 1.33 g/cm3 and 65.12 MPa, respectively. Chrysanthemum morifolium has a low cellulose content of 32.9% while the thermal resistance temperature was determined as 267.5 °C. Although its cellulose content is low, C. morifolium fiber can be a good alternative for many other reinforcement plant fibers in terms of tensile strength. The high tensile strength of the fiber can be attributed to the high crystallinity index and fiber morphology advantage (low lumen diameter and thick cell wall). Hollow fiber morphology can increase the insulation and absorption properties of the fibers and can also create a usage area in lightweight composites by providing low density. This study suggests a novel sustainable ecological reinforcement fiber for green polymer composites with low density, reasonable tensile strength, high surface hydrophobicity and high surface roughness.