Signe Magdalena Barth née Pettersson (16 June 1895, Uddevalla — 15 March 1982, Stockholm) was a Swedish painter and art teacher.

Raised on the Emaus estate near Uddevalla, she went on to study painting at Carl Wilhelmson's art college in Stockholm and then at Ernst Goldschmidt's school in Copenhagen.

[1] Her father tried to persuade her to return to Sweden but despite facing serious financial difficulties she decided to remain in Paris where she was free to study and paint.

[1] Her paintings, often revealing the influence of Césanne, include cityscapes of Paris and Stockholm and landscapes of the Swedish west coast.

[1] Her works are in the collections of Stockholm's Moderna Museet as well as in regional museums such as those in Borås, Östersund and Kalmar.