In military terms, 1st Regiment or 1st Infantry Regiment may refer to:
Australia edit
France edit
Germany edit
Greece edit
Poland edit
Spain edit
South Africa edit
- Durban Light Infantry, formerly 1st Infantry (Durban Light Infantry)
Thailand edit
- 1st Infantry Regiment, King's Own Bodyguards
United Kingdom edit
- 1st (Royal) Regiment of Foot
- 1st Regiment of Foot Guards
- 1st Regiment Greek Light Infantry
- 1 Regiment RLC, a unit of the Royal Logistic Corps
- 1 Regiment Army Air Corps