Martina Astner (née Hornbacher) is an Austrian vocalist known for contribution with bands Therion, Alas, Dreams of Sanity and Korova. In Dreams of Sanity, she formed duet with another female vocalist, Sandra Schleret. In 1998-1999 Martina was a participant of two Therion albums and she was also its live vocalist. In 2000s she was a member of Alas, project led by Erik Rutan.
She is currently a collaborator member of a media projects company called Subdivision's MediaPoint. She has also announced through her myspace page that she will be involved in a new triphop project called Underhill together with DJ Dean Rodell, which has been working on the studio throughout 2008.