Deficits have been observed in patients with chronic ankle instability while performing dynamic balance tasks. Foot orthotic intervention has demonstrated improvements in static balance following lateral ankle sprain, but the effect is unknown in patients with chronic ankle instability during dynamic balance tasks. Twenty patients with self-reported unilateral chronic ankle instability volunteered for participation. They completed a familiarization session and 2 test sessions separated by 4 weeks. The familiarization session consisted of practice trials of the Star Excursion Balance Test (SEBT) and Limits of Stability (LOS) test, orthotic fitting, and the Cumberland Ankle Instability Tool (CAIT) questionnaire. Patients were instructed to wear the custom-fitted orthotics for at least 4 hours a day to a preferred 8 hours a day for the 4 weeks between sessions. There was an increase in distance reached in the posterolateral direction over the 4-week period in the orthotic condition. There was an increase in distance reached in the medial direction, demonstrating an improvement on the injured side in the orthotic condition after 4 weeks of orthotic intervention. No consistent, meaningful results were observed in the LOS. The involved leg had a significantly lower CAIT score than the uninvolved leg during both sessions, but the involved leg CAIT scores significantly improved over 4 weeks compared with the baseline measure. Orthotic intervention may prove beneficial for improving dynamic balance as measured by the SEBT in individuals with chronic ankle instability and may be a useful adjunct to clinical and sport interventions.