A novel phenomenological model taking into account the creep-fatigue interaction in composite materials’ fatigue performance is introduced in this paper. The model is based on the derivation of a master curve by using existing experimental fatigue data from a wide range of composite laminates and adhesively bonded composite joints. The developed model can subsequently be used in order to predict the fatigue behavior of additional composite materials systems under different loading conditions (stress ratios) when a limited amount of fatigue data is available. The model predictions were validated by comparisons to experimental data and relevant predictions provided by other existing models from the literature.