Friedlander was born on 19 February 1928 in the East End of London to Jewish immigrants from Kiev, Russia. From the age of three she grew up in a Jewish orphanage in London with her sister Anne. She won a scholarship at the age of 14 and attended Camberwell School of Art, where she studied photography. From 1946 to 1957 she worked as an assistant to fashion Photographers Douglas Glass, an expatriate New Zealander, and Gordon Crocker. She married Gerrard Friedlander, a New Zealander of German Jewish origin, in 1957 and emigrated to New Zealand with him in 1958. She became a naturalised New Zealander in 1977.
Initially, the couple lived in Te Atatu South, and Friedlander worked as a dental assistant in her husband's dental practice. In 1964 she began working as a freelance Photographer, and in 1972 her work became well known through her collaboration with social Historian Michael King, photographing Maori women and their traditional moko tattoos. Friedlander considered this project the highlight of her career, and in 2010 she donated the series of 47 portraits to the national museum, Museum of New Zealand Te Papa Tongarewa.
Friedlander's photography career lasted over 40 years, during which time she photographed a diverse range of subjects, including famous and ordinary people, and rural and urban landscapes. Her work was published in books, magazines and newspapers such as Wine Review, New Zealand Listener and the British Journal of Photography. She held exhibitions at a number of galleries, including the Photographers' Gallery in London, the Wynyard Tavern in Auckland (1966) and the Waikato Art Museum (1975). In 2001, a retrospective exhibition of 150 of her photographs from 1957 to 1986 was held at the Auckland Art Gallery, followed by a tour of New Zealand galleries the following year. In 2006, Friedlander's work was included in an exhibition of contemporary New Zealand photography for the Festival Internazionale di Roma, which was subsequently also shown at the Pingyao International Photography Festival in China.
Friedlander's work was featured in the books Moko: Maori Tattooing in the 20th Century (1972) with Michael King; Larks in a Paradise (1974) with James McNeish; Contemporary New Zealand Painters A–M (1980) with Jim and Mary Barr; Pioneers of New Zealand Wine (2002) with Dick Scott; Marti Friedlander: Photographs (2001) with Ron Brownson and Marti Friedlander with Prof. Leonard Bell (2009). The book Marti Friedlander: Photographs was shortlisted at the 2001 Montana Book Awards.
Friedlander was appointed a Companion of the New Zealand Order of Merit for services to photography in the 1999 New Year Honours, and in 2004 she was the subject of a documentary by Shirley Horrocks entitled Marti: the Passionate Eye. In 2007 the Arts Foundation of New Zealand launched the Marti Friedlander Photographic Award, presented every two years to an experienced Photographer. In 2011 she received an Arts Foundation of New Zealand Icon Award. She was awarded an honorary Doctorate of Literature by the University of Auckland in 2016.
In 2013 Friedlander published an autobiography, Self-Portrait, written with oral Historian Hugo Manson.
In October 2016, Friedlander revealed that she was suffering from late-stage breast cancer. She died at her home in Auckland on 14 November 2016 aged 88. She was a member of the New Zealand Labour Party and photographed Prime Minister Norman Kirk in 1969.