Hertsmere is a local government district and borough in Hertfordshire, England. Its council is based in Borehamwood. Other towns in the borough include Elstree and Potters Bar.
Hertsmere is represented in Parliament by Conservative James Clappison.
The borough was originally in the Metropolitan Police District, despite being outside the modern Greater London boundaries. It was not transferred to Hertfordshire Constabulary until 2000.