We propose Adaptive Non-Local Gravity, a non-local extension of General Relativity in which parity-odd gravitational signatures are dynamically suppressed above a time-dependent cutoff. The cutoff is set by a rolling modulus via the comoving threshold k_star(eta) = a(eta) M(chi_bar(eta)), so only sufficiently low-frequency cosmological tensor modes experience a parity-violating response. Parity violation is implemented by a pseudo-scalar coupled to the dual Weyl tensor through a dual-exclusive non-local form factor acting on the foliation-projected spatial Laplacian Delta_perp defined on constant-chi hypersurfaces. Cosmological correlators are defined with a retarded in-in (Schwinger-Keldysh) prescription, ensuring causal response in linear perturbation theory. Because FLRW is conformally flat (Weyl = 0 on the background), the parity-odd sector does not modify the homogeneous expansion at leading order, while generating a scale-dependent tensor chirality imprint in the radiative sector. The central prediction is a tensor parity horizon: an exponential suppression of the inferred tensor chirality above a characteristic multipole ell_star ~ k_star,* D_star, producing a sharp turnover in parity-odd CMB polarization spectra TB and EB. We emphasize controlled validity in the linear transverse-traceless tensor sector around FLRW and outline a model-comparison strategy against smooth-running and scale-invariant chirality alternatives.