Stimulation of deep cortical structures has been demonstrated to provide symptomatic alleviation to people with depression, Parkinson's disease and epilepsy. However, electrodes used clinically for therapies requiring deep-brain-stimulation are currently limited to those that penetrate directly through delicate neural tissue following craniotomy or burr-hole surgery. Using an endovascular neural interface, the risks associated with open-brain surgery can be mitigated. Previously, we demonstrated proof-of-concept that a stent-electrode array can access the brain via blood vessels and can record high-fidelity neural information over a chronic duration. However, it was unknown whether focal stimulation could be delivered from within a cortical vessel. This work demonstrates that a stent-mounted electrode array can stimulate various regions of the sheep motor cortex to elicit visually observable and independent movements of the lip, face, jaw, neck and limb. While inter-animal differences were observed with respect to the elicited movement and stimulation threshold required to generate a response, there was reasonable consistency regarding the response and the location of the stimulating electrodes from the branching central sulcal veins. Six animals were observed to have multiple different and independent muscle movements time-locked to electrical stimulation.