The waiting times and energies of gamma-ray flares carry important information about activity properties and particles acceleration of a source. We investigate the memory and dynamics to gamma-ray flares from a typical blazar 3C 454.3 in the work. The rescaled range analysis method is used to estimate the Hurst exponent H for memory effect. The Pincus index (PI or the maximum approximate entropy) and the largest Lyapunov exponent (LLE) are measured to study the dynamics, i.e., randomness and chaos, of these gamma-ray flares. Our analysis discloses that the gamma-ray flare emissions from blazar 3C 454.3 demonstrate moderate memory effects with H ∼ 0.6–0.7 across both temporal and energy dimensions. In the PI–LLE plane, these sources are further characterized by high randomness (PI ∼ 0.8–1.0) coexisting with weak chaos (LLE ∼ 0). These statistical features resemble those of solar X-ray flares and radio/X-ray flare emissions from magnetars. Such properties are compatible with a magnetic reconnection scenario that powers gamma-ray flares of blazar 3C 454.3.