Hon. Mrs. Diana Elizabeth Geddes (née Swift) (22 August 1926-22 February 2011). was a Conservative Party politician.

The daughter of Brigadier Charles Copley Swift and Mabyn Hester Sievewright. She spent much of her youth with governesses in England while her father served in the Royal Engineers in India. With the outbreak of war she moved to India and became a volunteer nurse in Burma. She married the Hon. John Reay Campbell Geddes, son of Auckland Campbell Geddes, 1st Baron Geddes, in western India in 1944.

After the war the couple moved to England, living near Bristol. She became National Vice-Chairman of the Young Conservatives.

The couple moved to London and she was elected to the Greater London Council in 1970 to represent the London Borough of Lambeth. Three years later, following boundary changes she was elected GLC member for Streatham. She stood down from the council in 1977.

Following her husband's death in 1978 she moved to Ireland. She died in County Meath aged 84.