David Ross Howarth (born 10 November 1958) is a British academic and politician who was the Liberal Democrat Member of Parliament for Cambridge from 2005 to 2010.

In the 2005 general election he was elected Member of Parliament for Cambridge, defeating Labour MP Anne Campbell, overturning a majority of 8,579, and winning with a majority of 4,339 votes (securing 44% of the votes cast).

In 2008 Howarth criticised Home Office minister Vernon Coaker's defence of the policing of the Camp for Climate Action at Kingsnorth power station, which was widely criticised as disproportionate, and called on the government and police to end the practice of likening environmental protesters to terrorists.

[3] He was one of the relatively few MPs not implicated in the 2009 expenses scandal, being singled out by The Guardian as one of the "Angels" for having "not claimed a penny in second home allowances" and commuting the 60 miles from Cambridge to Westminster.

He was subsequently reinstated in his old job, as a Reader in Law and Land Economy at Cambridge University.