Iosif Markovich Ratner (Russian: Иосиф Маркович Ратнер; 26 August 1901 – 20 March 1953) was a Soviet military adviser with the Soviet embassies in Republican Spain and China during the Spanish Civil War and Second Sino-Japanese War.

A veteran of the Russian Civil War and 1929 graduate of the Frunze Military Academy, he was awarded the rank of major-general in 1944.

He taught at the Voroshilov General Staff Academy as a senior instructor during and after World War II.

He was a student of armored warfare in Weimar Germany in 1930, becoming fluent in the German, French, and Polish languages.

He was next named Deputy Chief at the 7th Section of the Main Directorate of Formation and Staffing from January to March 1942 and Senior Inspector for the 1st Section of the Main Directorate of Formation and Staffing from March to October 1942.