Diana Maddock (born 1947) is a politician in the United Kingdom. She was member of Parliament for Christchurch following a by-election in 1993 caused by the death of Robert Adley, but lost the seat at the 1997 election to Christopher Chope. She was made a peer in 1997 and now sits in the House of Lords as the Lib Dems housing spokesperson.

She is married to Alan Beith, MP for Berwick-upon-Tweed.