<p>We investigate quantum coherence in a hybrid cavity magnomechanical system incorporating a squeezed-magnon drive. By analyzing the Gaussian quantum coherence of the cavity, magnonic, and mechanical subsystems, as well as the total system coherence, we identify the critical roles of phase control, coupling strength, drive power, and thermal noise. We show that the squeezing amplitude and phase precisely modulate the effective magnon frequency and damping, enabling phase-dependent enhancement and nonreciprocal transfer of coherence. Our systematic parameter analysis indicates that increasing the driving power and the photon–magnon coupling enhances quantum coherence, whereas thermal decoherence degrades it. However, this effect is partially suppressed by magnon squeezing. The results show that squeezed magnons are a robust and tunable resource for controlling, stabilizing, and optimizing quantum coherence in cavity magnomechanical platforms, offering potential applications in hybrid magnonic systems and coherent quantum information processing.</p>