A physical improvement made in a leased asset in order to customize it for the particular needs of a tenant. Leasehold improvements can either be done by landlords or by tenants to increase the marketability of the asset. Changing the flooring, installing partitions, painting, and putting in customized light fixtures are some examples of leasehold improvement.

The undertaken leasehold improvements can revert to the lessor at the end of the lease period, as long as it is stipulated in the agreement. Also called tenant improvements.