Born as Maria Izadora Ussher Calzado, she was named in part for the legendary dancer, Isadora Duncan. Her father is choreographer and TV director Lito Calzado and her mother was the late Irish-Spanish-Filipina, Mary Ann Ussher. Iza's brother, Dash, is a member of Legit Misfitz, a Pinoy rap group.In the late 1990s, she finished her high school in Miriam College and after which finished her undergraduate education in the University of Santo Tomas with a degree in Fine Arts.

Before entering show business, she worked as a dubber. Iza started out as a guest teen star in the now defunct show, Click, which led to further roles. Iza won her first ever heroine role through the soap opera Te Amo with the Argentinean actor Segundo Cernadas.Iza Calzado bagged her original role in The Echo, the English-language remake of Filipino director Yam Laranas’ horror film Sigaw. Calzado will be sharing the screen with Hollywood actor Jesse Bradford, who was last seen in Clint Eastwood’s World War II epic Flags of Our Fathers. Bradford will portray an ex-convict who will get entangled in the troubles of a battered wife, to be played by Calzado. Although she will be reprising a role that won her an Urian Best Supporting Actress award in 2005, she still had to audition. One of her co-stars, Carlos de Leon, asked her if she is Hispanic because of her facial feature. She won Best Supporting Actress for 28th Gawad Urian. On January 18, 2008, Iza Calzado won the Model Star Award from the Korea Asia Model Award Festival.

Independent Short/ Full Length Film Credits (2009):
Dukot (2009), Bente (2009), Manila (2009), Fuschia (2009)

Previous Independent Short/ Full Length Film Credits:
Pinoy Blonde (2005),Blackout(2007), Mona: Singapore Escort (2007), Batanes (2007), Kusina (2008) , Adela(2008),

Mainstream Film Credits:
Milan, (2004) ,Annie B. (2004), Sabel(2004), Sigaw (2004), Ispiritista: Itay, may moomoo! (2005), Mulawin The Movie(2005), Moments of Love(2006), Eternity(2006), Shake, Rattle & Roll 8(2006), Ouija (2007), Desperadas(2007), The Echo (Hollywood Remake of Sigaw) (2008), One True Love (2008), Scaregiver(2008), Desperadas 2(2008), Sundo2009, Ang Panday (2009), Yaya & Angelina: The Spoiled Brat Movie (2009)

T.V. Series:
Click (2001). Kung Mawawala Ka(2001), Te Amo, Maging Sino Ka Man (2004), Encantadia (2005), Etheria: Ang Ikalimang Kaharian ng Encantadia(2005), Encantadia: Pag-Ibig Hanggang Wakas (2006), Atlantika(2006), Impostora (2007), Joaquin Bordado(2008), ESP(2008), LaLola(2008), Obra(2008), All About Eve(2008),Encantadia : Arizonia(2009), "All About Eve" (2009), "Kaya kong abutin ang langit" (2009)