Sofia Sigizmundovna Dzerzhinskaya (born Muszkat; Polish: Zofia Dzierżyńska—Muszkat; Russian: Софья Сигизмундовна Дзержинская—Мушкат; 4 December 1882 – 27 February 1968) was a leading Polish Social Democrat and later Communist politician.

[1][2] During World War II, she was director of the Polish language Tadeusz Kościuszko radio station, broadcasting the communist message into occupied Poland.

[3] From September 1918 through February 1919, Sofia was a member of the Soviet diplomatic mission in Bern.

In 1922, Sofia worked in the School of Rosa Luxemburg in Moscow, later, 1923–24 at the Communist University of the National Minorities of the West.

On 23 June 1911, in Pawiak prison, she gave birth to their only son and child Janek (Jan).