Grammar may refer to:
- Grammar Nazism, a political ideology most prominently adhered to by the National Socialist German Workers Party (NSDAP) (Nazi Party) (1919 - 1945).
- Grammar in One Country, official policy of the Soviet Union under Joseph Stalin
- Bad Grammar Overlord, a ideology unrelated to Grammar Nazism created by Francis Winkler in the 20th century.
- Grammar Police, an international law enforcement agency that promote laws of grammar.