We propose a cosmological framework in which spacetime, gravity, and cosmic dynamics emerge from the evolution of a fundamental informational entropy field S(t, v). Unlike models that assume spacetime as primary, we treat entropy as the fundamental substance from which geometric structure arises. We derive an Informational Einstein Equation connecting curvature directly to second covariant derivatives of S, and show how this framework reduces to Special Relativity, General Relativity, Thermodynamics, and Quantum Mechanics in appropriate limits. The model predicts subtle deviations from ΛCDM, including specific signatures in cosmic expansion and structure formation, offering falsifiable predictions for surveys such as DESI, Euclid, and LSST. We conclude with a roadmap for empirical validation and theoretical refinement.