Karl Georg Gustav Wüstnei (18 February 1810 – 12 October 1858) was a German theologian, naturalist and school teacher.
He collected numerous specimens of fungi, plants and insects from the Mecklenburg region.
Wüstnei was born in Malchin where his father was a physician.
He collected plants from the Mecklenburg region and also exchanged specimens from other parts of the world with collectors.
He took a special interest in the moss and lichens and edited two exsiccatae, namely Musci hepatici exsiccati Florae Megapolitanae and Sammlung mecklenburgischer Lebermoose.