In criminal and civil law, strict liability is a standard of liability under which a person is legally responsible for the consequences flowing from an activity even in the absence of fault or criminal intent on the part of the defendant.

Under the strict liability law, if the defendant possesses anything that is inherently dangerous, as specified under the "ultrahazardous" definition, the defendant is then strictly liable for any damages caused by such possession, no matter how careful the defendant is safeguarding them.

In the field of torts, prominent examples of strict liability may include product liability, abnormally dangerous activities (e.g., blasting), intrusion onto another's land by livestock, and ownership of wild animals.

Other than activities specified above (like ownership of wild animals, etc), US courts have historically considered the following activities as "ultrahazardous":

1. storing flammable liquids in quantity in an urban area
2. pile driving
3. blasting
4. crop dusting
5. fumigation with cyanide gas
6. emission of noxious fumes by a manufacturing plant located in a settled area
7. locating oil wells or refineries in populated communities
8. test firing solid-fuel rocket motors.

On the other hand, US courts typically rule the following activities as not "ultrahazardous": parachuting, drunk driving, maintaining power lines, and letting water escape from an irrigation ditch.

Traditional criminal offenses that require no element of intent (mens rea) include statutory rape and felony murder.