Despite the prevalence of stroke-induced gait impairment due to foot drop, current rehabilitative practices to improve gait function are limited, and orthoses can be uncomfortable and do not provide long-lasting benefits. Therefore, novel modalities that may facilitate lasting neurological and functional improvements, such as brain-computer interfaces (BCIs), have been explored. In this article, we assess the feasibility of BCI-controlled functional electrical stimulation (FES) as a novel physiotherapy for post-stroke foot drop. Three chronic stroke survivors with foot drop received three, 1-hour sessions of therapy during 1 week. All subjects were able to purposefully operate the BCI-FES system in real time. Furthermore, the salient electroencephalographic (EEG) features used for classification by the data-driven methodology were determined to be physiologically relevant. Over the course of this short therapy, the subjects' dorsiflexion active range of motion (AROM) improved by 3°, 4°, and 8°, respectively. These results indicate that chronic stroke survivors can operate the BCI-FES system, and that BCI-FES intervention may promote functional improvements.