Aphasia recovery after stroke depends on the condition of the remaining, extra-lesional brain network. Network control theory provides a unique, quantitative approach to assess the interaction between brain networks. In this longitudinal, large-scale, whole-brain connectome study, we evaluated whether controllability measures of language-related regions are associated with treated aphasia recovery. Using probabilistic tractography and controlling for the effects of structural lesions, we reconstructed whole-brain diffusion tensor imaging connectomes from 68 individuals (20 female, 48 male) with chronic post-stroke aphasia who completed a 3-week language therapy. Applying principles of network control theory, we computed regional 1) average and 2) modal controllability, which decode the ability of a region to 1) spread control input through the brain network and 2) to facilitate brain state transitions. We tested the relationship between pre-treatment controllability measures of 20 language-related left he...