In this work, the influence of fiber content on viscoelastic properties of Phoenix sp. fiber-incorporated composites was investigated. The composites were fabricated using compression molding process. The results revealed that the composite samples incorporated with 40% volume of Phoenix sp. fiber have better viscoelastic properties when compared to other composites investigated. A positive shift in glass-transition temperature was also noted with respect to the increase in fiber volume fraction. Moreover, the phase behavior of the composites was analyzed using Cole–Cole plot.