This Faculty Early Career Development Program (CAREER) award will advance the fundamental understanding of how soft elastic materials behave when they contain an internal fluid that can move, reorganize, and separate into distinct phases within the solid network. Fluid-saturated soft solids arise in a wide range of engineered and natural systems, including hydrogels, solid–liquid composites, biological tissues, and geological media. When these materials are subjected to mechanical loading, the embedded fluid can redistribute, interact with the surrounding elastic matrix, and in some cases undergo phase separation, thereby strongly influencing stiffness, stability, and resistance to failure. Despite their prevalence in both natural and technological contexts, the coupled relationship between mechanical deformation and fluid organization remains poorly understood, particularly when large deformations and evolving microstructures are involved. This project addresses this critical knowledge gap by developing a predictive framework that captures the two-way coupling between mechanical response and fluid organization in soft materials. In addition to advancing fundamental science, the knowledge generated through this research will support the design of next-generation soft composite materials, flexible biomedical implants, engineered tissue scaffolds, and emerging materials for energy storage. This CAREER award will also support an integrated educational program that strengthens the domestic Science, Technology, Engineering, and Mathematics pipeline through middle-school outreach, undergraduate research experiences in soft matter, and the integration of research discoveries into undergraduate and graduate curricula, while training students in modern computational and theoretical tools. The CAREER project will support research aimed at establishing a predictive theoretical and computational framework for the mechanics of fluid-saturated soft solids subjected to external