Cerebral palsy (CP) is a neuromotor disorder which can lead to walking difficulties. Functional electrical stimulation (FES) is approved by The National Institute for Health and Care Excellence (NICE) for managing foot drop in upper motor neuron disorders, however there is limited evidence for its use in CP. We discuss a cohort of 26 patients with CP using FES for a 3 month period and longitudinal data for a subset of 11 patients that have used FES for at least 4 years. Patients were referred for the following common barriers to walking: reported falls (54%), foot drop (46%) and tripping (15%). After application of FES at baseline, there was a small clinically insignificant orthotic effect on walking speed (0.01 m/s on/off difference). However, orthotic effects became statistically and clinically significant at three months of continuous use (0.12 m/s on/off difference, p = 0.01) and in the subset of 11 patients this remained significant at four years (0.24 m/s on/off difference, p = 0.01). Patient reported walking satisfaction (numerical rating scale) improved when comparing no-FES versus FES at three months and at four years. FES is a safe, cost-effective treatment option and should be considered, for adults with CP who have walking difficulties.