Non-use in trademark law refers to a situation where a registered trademark has not been used in commerce in connection with the goods or services listed in the registration for a certain period of time. This failure to use the trademark can result in the loss of the trademark rights or registration.

In many jurisdictions, trademark owners are required to use their trademark in commerce within a certain period of time after registration, typically within the first five years of registration, and then renew their registration periodically thereafter. Failure to use the trademark as registered or renew the registration can result in the trademark being vulnerable to cancellation or revocation.