Helen Medlyn MNZM (born 1958) is a New Zealand mezzo-soprano opera singer, musical theatre actor, media producer and gardener.

[9] Medlyn tended to perform comic or character roles, in part due to her vocal range as a mezzo-soprano.

[1] Roles played by Medlyn over the years include Madame Flora in The Medium,[10] Marcellina in The Marriage of Figaro,[11] Dame Quickly in Falstaff,[12] Prince Orlovsky in Die Fledermaus, Concepción in L'heure espagnole, Brangaene in Tristan und Isolde and Fräulein Schneider in Cabaret.

[16] Beginning in the 1980s, Medlyn collaborated with musical director and pianist Penny Dodd in a number of concerts and performances, including notably eight critically-acclaimed cabaret shows themed around the concept of hell between 2000 and 2010.

[4] In the 2013 Queen's Birthday Honours, she was appointed a Member of the New Zealand Order of Merit, for services to the performing arts.