Bored piles (drilled shafts) socketed in weathered rock mass are frequently used to transfer higher lateral loads from superstructures to competent underlying rock mass. A common method for analyzing the response of laterally loaded bored piles is to use nonlinear p–y curves to represent the rock mass resistance. This paper presents the development of a hyperbolic p–y criterion for flexible bored piles in weathered rock mass under static loading. The hyperbolic p–y criterion was derived based on the Hoek–Brown failure criterion. The ultimate The resistance of the rock mass and the initial stiffness of the p–y curve were proposed based on mathematical and statistical analyses. The effectiveness of the proposed p–y criterion was verified with finite-element analysis and full-scale tests. Finally, recommendations for choosing the rock mass parameters to establish the p–y curve were provided