In 1990 Allen & Unwin was sold to HarperCollins, and the Australian branch was the subject of a management buy-out.

[3] Frank Arthur Mumby and Frances Helena Swan Stallybrass,[4] Unwin's son Rayner S. Unwin and his nephew Philip helped him to run the company, which published works by Bertrand Russell, Arthur Waley, Roald Dahl, Lancelot Hogben and Thor Heyerdahl.

Allen & Unwin Australia Pty Ltd became independent in July 1990 by means of a management buy-out after the UK firm was bought by HarperCollins.

Among the many authors published by Allen & Unwin are Alex Miller, Christos Tsiolkas, Garth Nix, Jodi Picoult, Kate Morton, Michael Connelly, Thomas Keneally, Peter Corris, Paul Keating, Stephanie Dowrick, and Christopher Hitchens.

In 2017, Allen & Unwin refused to publish the book Silent Invasion due to legal concerns that it "would be targeted by Beijing and its proxies in Australia.