Isobel Ida Bennett AO 1984 (9 July 1909 – 12 January 2008) was one of Australia's best-known marine biologists.

She (with Elizabeth Pope) assisted William John Dakin with research for his final book (Australian Seashores[1]) regarded by many as "the definitive guide on the intertidal zone, and a recommended source of information to divers".

[4] She also wrote nine other books, and was one of the first women (along with Susan Ingham, Mary Gillham & Hope Macpherson) to go south with the Australian National Antarctic Research Expeditions (ANARE).

Isobel Ida Bennett was born in Brisbane in 1909 and educated at Somerville House leaving at the age of 16 when her family moved to Sydney.

[citation needed] In 1982 she was awarded the Mueller Medal by the Australian and New Zealand Association for the Advancement of Science.