Spearfish may refer to:
In geography:
- Spearfish, South Dakota, United States
- North Spearfish, South Dakota, United States
In biology:
- Marlin, or Spearfish, a fish with an elongated body, a spear-like snout or bill
In military:
- Spearfish torpedo, or simply Spearfish, is a modern torpedo built by GEC-Marconi
- Fairey Spearfish, a prototype dive bomber of the immediate post World War II period
- HMS Spearfish, a British S-class submarine lost in World War II
- USS Spearfish, a US submarine in World War II