The New Hampshire Department of Environmental Services (NHDES) is a state agency of the U.S. state of New Hampshire, headquartered in Concord.

The department works to "sustain a high quality of life for all citizens by protecting and restoring the environment and public health" in the state.

[1] The department is authorized under New Hampshire Revised Statutes Annotated (NH RSA) Chapter 21-O.

[1] Additionally, the New Hampshire Geological Survey is administratively attached to the department.

[1] In January 2022, a bill was introduced in the New Hampshire House of Representatives that proposed changing the name of the agency to New Hampshire Department of Environmental Protection.