The full skin friction and full end-bearing resistances of a single pile are not mobilized at the same displacement, while the conventional approach often oversimplifies by adding the skin friction to the end-bearing resistance as independent calculation steps. This paper presents a simplified interaction approach for the nonlinear load–settlement analysis of a single pile considering simultaneously the degradation of skin friction resistance and end-bearing resistance hardening under varying loads. The ability to estimate the load–settlement response of piles based on either needed loads or settlement is a special benefit of the proposed approach over existing methods. In addition, the proposed model is able to separate the skin friction resistance, end-bearing resistance, and elastic compression at arbitrary settlement. The analytical method shown a satisfactory performance as compared to experimental results for three extensively studied field test situations. The suggested approach shows promise as a suitable solution for the design optimization as well as the preliminary analysis to organize a suitable loading test program. A parametric analysis is conducted to further examine the influence of various significant parameters related to the load–settlement response of piles.