| Defending the Nation Obrana národa | |
|---|---|
  The Flag and the Symbol of Obrana národa | |
| Active | 10 January 1939 |
| Country | 
Czechoslovakia |
| Allegiance | Czechoslovak government-in-exile |
| Role | Armed forces of the Czechoslovak Underground State and the Czechoslovak Government-in-Exile |
| Size | 200,000 (1944) |
| Motto | "Nedáme se!" ("We will never surrender!") |
| Engagements | World War II |
| Commanders | |
| Current commander |
Josef Bílý Bedřich Homola Alois Eliáš František Bláha Sergej Vojcechovský |
Obrana národa (ON) (English: Defending the Nation) was the dominant Czechoslovak military resistance movement in German- and Hungarian-occupied Czechoslovakia. It was formed in January 1939, and over the next two years, it absorbed most other Czechoslovak underground forces. Its allegiance was to the Czechoslovak Government-in-Exile, and it constituted the armed wing of what became known as the "Czechoslovak Underground State".