He played together with his brother, Fritz Walter, at the club 1. FC Kaiserslautern. They also played together for the Germany national football team in the 1954 FIFA World Cup. Ottmar scored 4 goals in the tournament as West Germany won their first ever World Cup title. In total, Ottmar earned 21 caps and scored 10 goals for Germany.

During World War II, Walter was drafted into the Kriegsmarine and suffered heavy injuries in his right knee. After several operations, he was forced to end his career in 1958.