We report the first Ethiopian case of a rare neurologic complication, Guillain-Barre Syndrome (GBS), following Ad26.COV2.S (Janssen/Johnson & Johnson) COVID-19 vaccination. Although a temporal relationship is identified, a causal relationship between the Janssen/Johnson & Johnson COVID-19 vaccine and GBS is not established. Clinician awareness of this association is essential to early GBS diagnosis and treatment. Further, global data collection is important to ascertain the true magnitude and possible causality of post-COVID-19 vaccine associated GBS.