Violet Emily Wegner, Countess Brunetta d'Usseaux, Princess Ljubica of Montenegro (1887 – 17 October 1960), was a British singer who made a career in the music halls from the age of 15 and became known as the "Idol of Berlin".

In 1912, Violet married her first husband, Comte Sergio Francesco Enrico Maria Brunetta d'Usseaux (born 3 March 1885, Torino, Italy), in London.

Sergio's parents were Comte Eugenio Brunetta d'Usseaux and his wife, Ekaterina Alexandrovna Zeyffart (1859-1897), a rich Russian noblewoman of German and Ukrainian ataman descent.

After her marriage Violet converted to Orthodox faith and became HRH Princess Ljubica of Montenegro and thus sister-in-law to Queen Elena of Italy, as well as a host of other European princes and kings via her husband's siblings.

Violet did not forget her former profession and those who 'trod the boards,' however: the only wreath to be sent by a member of any royal family to the funeral of the celebrated Lillie Langtry in Jersey on 23 February 1929 was sent by the Prince Peter and Princess Ljubica of Montenegro.