Hannah Leah Mancini, also known professionally by her first name and the stage name Stella Mercury, is an American singer-songwriter who lives and works in Slovenia. Her musical styles encompass dance, dubstep and EDM.

After failing to represent her adopted country for the 2011 Contest alongside singers Sylvain and Mike Vale, she was internally selected to represent the country at the Eurovision Song Contest 2013 in Malmo with the song Straight Into Love, finishing last of 16 countries in the first semi-final. The following year, she co-wrote the song Round and Round with her eventual successor Tinkara Kovač for the contest in Copenhagen, which qualified for the final.