Housatonic Area Regional Transit, known popularly as HARTransit (formerly as HART), is the provider of public transportation for Danbury, Connecticut and surrounding communities.

The name was changed to Housatonic Area Regional Transit in 1979 after the addition of other municipal members.

The agency receives funding from municipal contracts, the Connecticut Department of Transportation, Federal Transit Administration and (on a limited basis) the New York State Department of Transportation.

Prior to HARTransit's establishment, Danbury had gone without transit service since 1967 when the privately owned ABC Bus Company which had replaced the Candlewood Bus Company a few months before, ceased operations.

The municipalities served by HARTransit are as follows: HART currently provides the following services: HARTransit's fleet is made up of Gillig fixed-route buses (35' BRT Low Floor series and a single low floor trolley) and Ford cutaway minibuses with Goshen Coach and StarTrans bodies.