Adelaide Writers' Week (AWW), known locally as Writers' Week or WW, is a large and mostly free literary festival held annually in Adelaide, the capital of South Australia in February and March. It forms part of the Adelaide Festival of Arts and comes under its governance. Writers' Week is held outdoors in the Pioneer Women's Memorial Garden, where attendees meet, listen, and discuss literature with Australian and international writers in "Meet the Author" sessions, readings, and lectures.

Each Adelaide Writers' Week includes six days of free panel-sessions presented live in the gardens, later made available online via podcast. Selected sessions are shown live via videolink in some libraries. There are also free events for children and young adults, at which children's authors present their work for a range of ages, and other activities take place. The programme also features a series of ticketed special events, both at Adelaide Festival time and throughout the year.

The first Adelaide Writers' Week was held in 1960 as part of the Adelaide Festival of Arts, biennially in March. It is the longest-running dedicated writers' festival in Australia. The first event was organised by a committee headed by state librarian Hedley Brideson, in collaboration with the Fellowship of Australian Writers (SA). Initially intended as a forum for writers, the event soon became popular with the public, in particular when guests included famous writers such as Russian poet Yevgeni Yevtushenko in 1966, followed in the early 1970s by Anthony Burgess, Edna O'Brien, John Updike, and Allen Ginsberg. In those years it was held at the State Library and University of Adelaide, which proved too small to accommodate audiences, so in 1976 was moved to the Pioneer Women's Memorial Garden, alongside King William Road next to the Torrens Parade Ground. At this time, the event took place under one tent.

The event soon grew, and publishers were drawn by the commercial opportunities. In 1986 a second tent was added to allow two sessions to run contemporaneously. From 2012, along with the Festival, Writers' Week became an annual event, based on an election promise by Premier Mike Rann.

In some years, WW has been dedicated to a writer; these have included Colin Thiele, Thomas Shapcott, Margo Lanagan, Christopher Koch, Judith Wright, Jessica Anderson, A. D. Hope, and Alexis Wright.

It has grown bigger year by year. In 2014, graphic novels and comics, represented by their authors and illustrators, were showcased in a dedicated one-day program.

Palestinian-American author Susan Abulhawa, a participant of the 2023 Adelaide Writers' Week, had previously shared a tweet from Russian president Vladimir Putin stating "DeNazify Ukraine", and was critical of Ukraine president Volodymyr Zelenskyy, labelling him a "depraved Zionist" and "more dangerous than Putin". Maria Tumarkin, a Ukrainian-born Australian historian and writer, along with Ukrainian writers Olesya Khromeychuk and Kateryna Babkina, withdrew from the event in protest at Abulhawa's inclusion. The South Australian Government under Peter Malinauskas and the Association of Ukrainians in South Australia condemned Abulhawa's comments, and sponsor MinterEllison withdrew its support for the festival. Festival director Louise Adler responded, "Adelaide Writers' Week is not in the business of cancelling people whose opinions may be objectionable to other groups or individuals".

In its 40th edition in 2025, Writers' Week was attended by around 160,000 over the six days, breaking previous records.