Antonie Langendorf (born Anette Glanzmann: 3 January 1894 – 23 June 1969) was a German political activist and politician (SPD, USPD, KPD).

In 1910 she relocated to Mülhausen, at that time in the extreme southwest of Germany, where her father worked as a senior trades union official.

1910 was also the year in which she joined the Social Democratic Party ("Sozialdemokratische Partei Deutschlands" / SPD), which had been permitted to participate in national elections since 1890, but was nevertheless still regarded by most members of the mainstream political establishment as an extreme left-wing organisation.

The political backdrop changed dramatically in January 1933 when the Nazis took power and converted Germany into a one-party dictatorship.

On her release she fled to Switzerland, but she then returned to Germany and continued her now illegal party activities and communist resistance work.

Antonie joined the breakaway Independent Social Democratic Party ("Unabhängige Sozialdemokratische Partei Deutschlands" / USPD).

Mannheim was in the US occupation zone which was part of the territory that would be relaunched in May 1949, as the German Federal Republic (West Germany).

Slightly unusually, it was accepted that Antonie Langendorf should continue as a member regional Landtag for several more years, now without any party affiliation.