Hannah Leah Mancini (born 12 March 1978), also known as Stella Mercury or simply Hannah is an American singer who works and lives in Slovenia. She has been heavily involved in dance, nu disco and electronic scenes, there, and has had the opportunities to work with a diverse group of first-rate artists and producers in these genres. Hannah's first music industry experiences had her on multiple soundtracks for Disney films and the opportunity to collaborate with Grammy winning producer, Larry Klein. She also performed at Radio City Music Hall, Universal Amphitheatre and on The Tonight Show with Jay Leno.

Mancini was the Slovene representative in the Eurovision Song Contest 2013 in Malmö, Sweden and co-wrote the Slovene entry, "Round and Round" in the Eurovision Song Contest 2014 in Copenhagen, Denmark.