  We apply a recent proposal to define "gravitational entropy" to the expansion
of cosmic voids within the framework of non-perturbative General Relativity. By
considering CDM void configurations compatible with basic observational
constraints, we show that this entropy grows from post-inflationary conditions
towards a final asymptotic value in a late time fully non-linear regime
described by the Lemaitre-Tolman-Bondi (LTB) dust models. A qualitatively
analogous behavior occurs if we assume a positive cosmological constant
consistent with a $\Lambda$-CDM background model. However, the $\Lambda$ term
introduces a significant suppression of entropy growth with the terminal
equilibrium value reached at a much faster rate.
