The Coblinine Nature Reserve is located in the Avon Wheatbelt bioregion of Western Australia.

It stretches along the Coblinine River, from its southern end east of Katanning, to Dumbleyung Lake.

[1][2] It was gazetted on 4 September 1908 and has a size of 41.67 square kilometres (16.09 sq mi).

[1] The nature reserve stretches through the localities of Ewlyamartup and Coblinine in the Shire of Katanning through Bullock Hills, Datatine and Dumbleyung in the Shire of Dumbleyung.

[2] The name Coblinine is of Koreng Noongar origin, meaning "all of the stomach intestines and navel, river-like, are here sitting".