Anna Sophie Magdalene Frederikke Ulrikke (born in 1730 or 1740 – dead 1804) was a Danish con-artist who in 1766 demanded a pension from the Danish royal house with the claim that she was the illegitimate daughter of king Christian VI of Denmark and the king's sister-in-law, the Dowager princess of Ostefriesland, Sophie Caroline of Brandenburg-Kulmbach (1707–1764).
Sophie Caroline of Brandenburg-Kulmbach had lived at the Danish court as a widow after 1735, and it was a widespread rumour that she had a relationship with her brother-in-law. Anna's story was backed up by a Norwegian student, Kirchhof, who was her lover. In 1770, a commission was organized to examine the case. After it was discovered, that Anna had been a prostitute in Amsterdam, her claims was deemed false, and she was placed in a work house. She was later released for good behaviour and given a pension of 100$. The date of birth is given as either 1730 or as 1740/41. If it was 1730, she could not have been the daughter of Christian VI of Denmark and Sophie Caroline of Brandenburg-Kulmbach, as the latter did not live at the Danish court until 1735.