Nancye Lee Bertles AM (née Hayes; born January 1943), billed under her maiden name as Nancye Hayes, is an Australian actress, dancer, singer and choreographer/director and narrator. She has been a leading figure in Australian musical theatre since the 1960s. Although her roles have been almost exclusively in theatre, she has briefly worked in television as a character actress, filling in for Judy Nunn on the soap opera Home and Away.

Nancye Hayes was born in 11th January 1943. She grew up in the Sydney suburb of Manly, an only child. At the age of seven, she had an operation to remove a growth in her hip joint, and the recovery included strapping her leg with irons. After her father died in a car crash when Hayes was eleven, her mother became a barmaid at the old Pacific Hotel in Manly. Nancye attended Stella Maris College, Manly, a Catholic school run by the Sisters of the Good Samaritan.

She began dancing lessons at age nine at Hazel and Violet Meldrum's studio. Hazel had been a choreographer for the leading Australian theatrical firm J. C. Williamson's.

Hayes, aged eighteen, left a job at a Sydney office to join the chorus of an Australian production of My Fair Lady. From 1963 she understudied or played small roles in productions such as the musical How to Succeed in Business Without Really Trying, My Fair Lady, Promises Promises, Hello, Dolly! and The Boys from Syracuse for J. C. Williamson's. She also performed in Kiss Me, Kate, Brigadoon, Annie Get Your Gun and Little Me at the Menzies Theatre Restaurant in Sydney.

In 1967, Hayes received wide notice playing the title role in the original Australian cast of Sweet Charity.

Over the next thirty years, she performed leading roles in Australian casts of many musicals including Fastrada in Pippin (1974), Lily St. Regis in Annie (1978–1979), Roxie Hart in Chicago (1981–1982), Miss Adelaide in Guys and Dolls (1986–1987), Mrs Lovett in Sweeney Todd (1987), Liliane La Fleur in Nine (1987–1988) and Dorothy Brock in 42nd Street (1989–1993). She later played supporting roles including Aunt Eller in Oklahoma! (The Production Company, 2005), Mrs Higgins in My Fair Lady (Opera Australia, 2008), Madame Armfeldt in A Little Night Music (Opera Australia, 2009) and Edith Bouvier Beale in Grey Gardens (The Production Company, 2011).

Since the 1980s Hayes has also appeared in many Australian-written musicals. These include Songs from Sideshow Alley (Classic Corporation, 1980), Variations (Nimrod Theatre, 1982), Summer Rain (Sydney Theatre Company, 1989), Jonah Jones (STCSA, 1991), Eureka! (Essgee, 2004) and Metro Street (STCSA, 2009). She appeared in the Australian Broadcasting Corporation television special on Australian musicals Once In A Blue Moon and its soundtrack recording. Hayes appeared in Hayes @ the Hayes (Hayes Theatre, 2019), a biography of her life devised by Tony Sheldon.

Her drama credits for Australia's major theatre companies and commercial producers include Born Yesterday, Danton's Death, Same Time, Next Year, Going Home, Dusa, Fish, Stas and Vi, The Glass Menagerie, Steel Magnolias, Stepping Out, and The Importance of Being Earnest. Her cabaret show, Nancye with an E, toured Australia in 1992. In 2006, she performed with Todd McKenney in his first non-musical role in the Ensemble Theatre's production of Six Dance Lessons in Six Weeks at the Playhouse Theatre in the Sydney Opera House. It became the theatre's most successful play ever, and the pair re-united ten years later for another season along with Sandra Bates in her final directorial role.