The Ostrava City Marathon is a road running event held annually in September on Masaryk Square in Ostrava, Czech Republic, featuring a marathon as its primary competition. Established in 1954, it holds the distinction of being the nation's longest-running marathon. The event's current format includes a half marathon, a 10 km race, a relay, and a charity MiniMarathon.
The course is designed to showcase Ostrava's diverse character, covering its historic downtown, industrial heritage, and parklands. While Czech and former Czechoslovak athletes have frequently secured victories, notable exceptions include repeat wins by Kazimierz Orzeł from Poland and Sigrun Macheleidt of East Germany. The race was temporarily suspended following the passing of its original organizer, Slávek Mozga. It resumed in the 1970s and has subsequently hosted the national championship on multiple occasions. Female participation in the marathon began upon its revival, and a female finisher has been recorded in nearly every edition since the mid-1980s.