Theodor Johannes Adolph Gerdener (19 March 1916 – 21 November 2013) was a South African politician and author.

You can help expand this article with text translated from the corresponding article in Afrikaans. (December 2013) Click [show] for important translation instructions. View a machine-translated version of the Afrikaans article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Afrikaans Wikipedia article at [[:af:Theo Gerdener]]; see its history for attribution. You should also add the template {{Translated|af|Theo Gerdener}} to the talk page. For more guidance, see Wikipedia:Translation.

Born in Cape Town, Gerdener served as an interior minister for the National Party. He resigned from the National Party, and founded and chaired the Democratic Party from 1973 to 1977. He was Administrator of the Natal Province between November 1961 and August 1970.

Theo Gerdener died on 21 November 2013, aged 97, in Pretoria.^[1]