Gun Margareta Winberg (born Gustafsson 13 August 1947) is a Swedish Social Democratic politician.

She became a very controversial figure in the public debate, after an interview she gave to the Swedish documentary The Gender War in 2005.

In the second part of the two-part documentary, Winberg expressed strong support for radical feminism, for the ideologist Eva Lundgren, and for requiring institutes of higher education to teach feminist theory as fact, in order to change society.

[3] Within the Social Democrats, she had a euro-sceptic profile, and was one of two ministers campaigning for the "no" side in the 1994 referendum on Sweden's membership in the European Union.

She similarly was against adopting the euro, but as deputy prime minister, she held a low profile in the 2003 referendum on the issue.