Tessa Staveley was born in 1940 in Auckland, the daughter of a doctor. Her entire school career was spent at Diocesan School for Girls . As a teenager she competed in the butterfly and medley stroke swimming, becoming the national butterfly and medley record holder (1958—59) and winning a silver medal for 110 yards butterfly at the 1958 British Empire and Commonwealth Games. She was named New Zealand Swimmer of the Year in 1959.

After leaving school she worked as a journalist for the Auckland Star, before travelling to Europe, working for the Daily Express. She married John Duder in 1964 and following the birth of the first of her four daughters, she was a full-time mother for 7 years, much of it spent in Pakistan. She returned to Auckland in 1972, where she reentered the work force as a pianist.

Tessa Duder began writing fiction in 1977. Her first novel Night Race to Kawau was published by Oxford University Press in 1982. Her most successful works are the Alex quartet of novels, which builds upon her own childhood experiences, by following a teenage competitive swimmer at Epsom Girls Grammar School;- (Alex, Alex in Winter, Alessandra: Alex in Rome and Songs for Alex). The series won three New Zealand Children's Book of the Year awards and three Esther Glen medals. Alex has been translated into 5 languages and is Penguin New Zealand's best selling work of fiction. A film production of Alex was released in 1993 but was commercially unsuccessful.

Tessa Duder's later work has not been as successful although The Tiggie Tompson Show won the 2000 New Zealand Post Senior Fiction Award for young adult fiction. Her first work for adults, a Short Story collection Is She Still Alive? reached No 2 on New Zealand best seller lists in 2008

Tessa Duder has performed in several of her own plays and acted in 11 episodes of the New Zealand soap Shortland Street.

She is a past president of the NZ Society of Authors (PEN NZ Inc). She has been awarded the OBE and the Margaret Mahy Medal.

As of 2009 she lives with her husband in Mission Bay, Auckland, New Zealand.,

Novels for young people:

• Night Race to Kawau (1982)
• Jellybean (1985)
• Alex (1987)
• Alex in Winter (1989)
• Alessandra - Alex in Rome (1991)
• Songs for Alex (1992)
• Mercury Beach (1997)
• The Tiggie Thompson Show (1999)
• Hot Mail (2000)
• Tiggie Thompson, All at Sea (2001)
• Tiggie Thompson's Longest Journey (2003)

Short Stories for Adults;

• Is She Still Alive? (2008)

Plays:

• The Runaway (1993) - one-act play for young actors about Joan of Arc
• The Warrior Virgin (1996)

Non-Fiction:

• Kawau - the Governor's Gift (1981)
• The Book of Auckland (1985)
• Spirit of Adventure: the Story of New Zealand's sail training ship (1985) — with Captain Barry Thompson and Clifford Hawkins
• Waitemata - Auckland's Harbour of Sails (1989)
• Journey to Olympia - the story of the Ancient Olympics (1992)
• The Making of Alex: the movie (1993)
• In Search of Elisa Marchetti ... a writer’s search for her Italian family (2002)
• Margaret Mahy - a writer's life (2005)