Watford Museum is a local museum in Watford, Hertfordshire, in the United Kingdom. It is owned by Watford Borough Council and is located on the Lower High Street in Watford. The museum opened in 1981 and is housed in a Grade II-listed Georgian town house which was previously the premises of Benskins Brewery.

Its collection includes fine art, displays about local heritage, industry and sport, with a special collection related to the history of the Cassiobury Estate.

The Museum has a significant Fine Art collection, which includes the notable Cassiobury Collection. Works on display include artworks formerly of the Earl of Essex’s collection at Cassiobury House, with paintings of the Cassiobury Estate such as A view of Cassiobury Park by John Wootton, View of the South-West Front of Cassiobury House by J. M. W. Turner, Cassiobury Park Gates by Charles Vickers and an 1831 painting of the Cassiobury House Winter Dining Room by William Henry Hunt. The museum also houses portraits of a number of Earls of Essex.