He is one of New Zealand's most distinguished and prolific authors, having written over thirty novels for adults and children, and has won numerous awards both in New Zealand and overseas, including multiple top prizes at the New Zealand Book Awards, the James Tait Black Memorial Prize in the UK, the Katherine Mansfield Menton Fellowship, the Robert Burns Fellowship and a Prime Minister's Award for Literary Achievement.

Gee was born in Whakatāne, and brought up in Henderson, a suburb of Auckland, a location that frequently features in his writing.

[6][7] Gee attended Henderson Primary School and Avondale College, and completed BA and MA degrees at the University of Auckland, which subsequently recognised him with a Distinguished Alumni Award in 1998, and an honorary Doctorate of Literature in 2004.

[9] Gee began writing at university, and had short stories published in New Zealand journals Landfall and Mate.

[1] After finishing his MA he taught in the secondary department of Paeroa District High School for about 18 months, starting in February 1955, but resigned in July 1956 to focus on his writing.

[1] In 1964, Gee was the sixth recipient of the Robert Burns Fellowship at the University of Otago, one of New Zealand's most prestigious literary awards.

[17] This novel was later adapted into the critically acclaimed film of the same name by director Brad McGann in 2004.

[7] Gee has described it as his "grandfather novel", with the character George Plumb closely based on his mother's father James Chapple, particularly his early life and his trials for heresy and seditious utterance.

[19] The novel and its two sequels, Meg (1981) and Sole Survivor (1983), explore the impacts of history, politics and religion on one family from the perspectives of different members.

[19] At this time Gee also published his first children's novel, Under the Mountain (1979), a science fiction story set in Auckland, New Zealand, about 11-year-old twins who discover aliens under volcanic Lake Pupuke.

[9] Around this time he wrote two adult novels set in Nelson: Prowlers (1987)[31] and The Burning Boy (1990).

[19] In 1993, Andro Linklater, writing in British newspaper The Sunday Times, said that "Gee deserves to be regarded as one of the finest writers at work, not only in New Zealand ... but in the English speaking world".

[36][21] Gee was the 1992 recipient of the Katherine Mansfield Menton Fellowship, a literary fellowship that enables the recipient to work in Menton, France, for part of the year, where Katherine Mansfield herself lived and worked in the early 20th century.

[19] Other notable works in the late 1990s included the children's books Orchard Street (1998) and Hostel Girl (1999).

[19] Salt and its sequel, Gool, were both listed as Storylines Notable Young Adult Fiction Books.

[47] Gee's novels are commonly set in New Zealand, often in fictitious versions of Henderson, where he grew up.

[46] Gee said in 2018 that meeting Margareta changed his life: "I was 38 when we got together and was drifting and wasting my time and only pretending to be a writer.