The Soviet order of battle for the invasion of Poland in 1939 details the major combat units arrayed for the Soviet surprise attack on Poland on September 17, 1939. As a result of joining battle after the Germans had already launched their invasion, the Soviets, prepared for battle in secrecy, met comparatively limited resistance. Several skirmishes between the German and Soviet forces did occur, but neither government was prepared for starting a larger conflict, and these were soon referred to as "misunderstandings".
Before the invasion there were created two "fronts" as a form of the Army Group based on Byelorussian Special Military District (BOVO) into the Byelorussian Front and Kiev Special Military District (KOVO) into the Ukrainian Front.
Like the Germans, the Soviets employed two primary offensive axes, each managed by a Front. Each Front commander had at his disposal a mobile group of forces created from cavalry and mechanised troops; a precursor of the cavalry-mechanised groups of the Second World War.
The effects of the purge are visible in the ranks of the commanders in the order of battle, with only one Army commander serving in the appropriate rank of Komandarm, in this case 2nd Class (Komandarm 2nd rank, ), the rest serving in being Corps (Komcor) and Divisional (Komdiv) Commander rank ()
Covered north-eastern sector of Polish front from Byelorussian Special Military District<br> <big>Komandarm 2nd rank Mikhail Kovalyov</big><br> Chief of Staff Komkor Maksim Purkayev
Polotsk Army Group<br> Komkor Vasily Kuznetsov
Minsk Army Group<br> Komdiv
BSSR Border Troops<br> Kombrig Ivan Bogdanov
Dzerzhinsk Cavalry-mechanised Group<br> Komkor Ivan Boldin
Covered southern sector of Polish front from Kiev Special Military District<br> <big>Komandarm 1st rank Semyon Timoshenko</big><br> Chief of Staff Kombrig Nikolai Vatutin
Shepetovka Army Group<br> Komdiv Ivan Sovetnikov
UkrSSR Border Troops<br> Komdiv
Volochysk Army Group<br> Komkor Filipp Golikov
Kamienets-Podolsky Army Group<br> Komandarm Ivan Tyulenev