In addition to supporting vertical loads from superstructures, piles are frequently subjected to horizontal soil pressures, long-term wind, wave, and current forces, as well as seismic loads. Presently, the p-y curve method is widely employed for calculating the horizontal forces acting on piles due to its ability to replicate the nonlinear interaction between piles and soil. This paper provides a thorough review and analysis of the current research on p-y curve models for piles, examining literature across various conditions such as horizontal static loads, cyclic loads, and seismic loads. Special emphasis is placed on the development, classification, and analysis of the key factors influencing major p-y curve models. It also discusses future research directions and prospects, considering emerging trends and prevailing challenges in the field. For instance, future studies should investigate p-y curves for piles under various combined loads, considering the influence of construction methods and the installation effect. Additionally, the development of a comprehensive p-y curve database and the application of existing research to new foundation systems are essential for advancing pile technology and fostering innovative designs.