Order No. 227 (Russian: Приказ № 227, romanized: Prikaz No. 227) was an order issued on 28 July 1942 by Joseph Stalin, who was acting as the People's Commissar of Defence. It is known for its line "Not a step back!" (Ни шагу назад!, Ni shagu nazad!), which became the primary slogan of the Soviet press in summer 1942.

The order established that each front must create one to three penal battalions (Shtrafbats), which were sent to the most dangerous sections of the front lines. From 1942 to 1945, a total of 422,700 Red Army personnel were sentenced to penal battalions as a result of courts-martial. The order also directed that each army must create "blocking detachments" at the rear that would shoot "panic-mongers and cowards". In the first three months, blocking detachments shot 1,000 penal troops and sent 24,000 to penal battalions. By October 1942, the idea of regular blocking detachments was quietly dropped.

Intended to galvanise the morale of the hard-pressed Red Army and emphasize patriotism, it had a generally detrimental effect and was not consistently implemented by commanders who viewed diverting troops to create blocking detachments as a waste of manpower. On 29 October 1944, blocking detachments were disbanded by Stalin's order No. 349 citing the changed situation at the front.