Mariane Theresia Sophie (Maria Sofia) Stebnowska also called Zofia Stępkowska or Stempkosta (13 July 1753 or 1761 – 16 February 1848) was a Swedish opera singer and harpist of Polish origin.

She has been referred to as one of the more notable stage artists of the Gustavian era Royal Swedish Opera.

At their wedding, they were granted the use of the Villa Canton at Drottningholm by king Gustav III of Sweden.

Sophie Stebnowska was engaged at the Royal Swedish Opera in December 1782 and given a contract for life as a premier actress on 25 February 1790.

Gustav Löwenhielm mentioned her importance in Swedish theater and opera history in the 19th century, during a discussion about the employment of foreign artists, when he pointed out that several of the artists during the foundation of the Royal Swedish Opera and the Royal Dramatic Theatre had been foreigners: "Is it impossible to engage Mr Berg and Miss Schoultz?