This document presents the Ontological Primacy Framework (OPF), a philosophical and epistemological structure proposing that ontology is causally and structurally prior to mathematics. OPF formalizes the idea that mathematical objects, truths, and symbols are projections of a generative ontological substrate, not autonomous entities. Combining Aristotelian metaphysics, Popperian falsifiability, and symbolic epistemology, the OPF defines a hierarchy 𝒪 → ℳ governed by a non-invertible projection φ, where ontology (𝒪) encodes causality, identity, and temporal structure, and mathematics (ℳ) is derivative, symbolic, and non-generative. The work introduces:- The Onto-Mathematical Hierarchy Principle (OMHP)- A system of 35 falsifiability tests (20 epistemic, 15 mathematical), all passed- The OOP (Ontologization of Postulates) method for handling ad hoc structures- Formal derivations of projection conditions, identity preservation, and symbolic validity OPF challenges mathematical platonism, reductionist metaphysics, and postulate-driven scientific frameworks. It reestablishes being, cause, and ontological coherence as the foundation of all symbolic systems, offering a robust alternative for scientific theory validation, foundational physics, and AI epistemology. This preprint is part of the NonPhy research line and connects structurally to the HIGGS system of symbolic falsifiability, the FATE suite of epistemic tests, and the DOMUS ontology-based model infrastructure.