We propose Axion-Like Scalar Gravity (ALSG), a minimal extension of ΛCDM introducing a single axion-like particle (ALP) from the string-theoretic axiverse, active at late times. Inspired by quantum oscillatory dynamics, ALSG features an ALP with mass mϕ ≈10−14 eV, oscillating at fϕ ≈2.4 Hz, coupling conformally to baryonic matter via an effective field theory (EFT) framework with broken scale invariance. This screened coupling modulates the Hubble expansion and gravitational potentials, producing sub-percent oscillatory signatures in galaxy clustering, CMB residuals, and pulsar timing residuals. With three parameters and full compatibility with General Relativity (GR), ALSG addresses Hubble (H0) and S8 tensionswhile preserving early-universe consistency. Predictions are testable with Euclid, Si-mons Observatory, and NANOGrav, offering a falsifiable model grounded in particlephysics and cosmology, with multi-probe consistency to resolve degeneracies.