Horner syndrome was identified in 25 of 30 777 avian admissions to Currumbin Wildlife Hospital during 2010–2016. Unilateral ptosis and erection of facial feathers were distinct findings on physical examination and consistent across 9 species. Affected birds were biased toward adults (64%) suffering traumatic injuries (88%). Concurrent injuries requiring treatment were present in 38% of cases, and 76% had additional neurologic deficits. Prognosis for release was poor, with an overall success rate of 32%. Resolution of clinical signs increased to 44% with higher doses of meloxicam and required an average hospitalization of 22 days (range, 3–78 days). Further investigation of the underlying causes of Horner syndrome in birds to provide treatment and prognostic guidelines is warranted.