Wahlenbergiella mucosa is a species of saxicolous (rock-dwelling), crustose lichen in the family Verrucariaceae.

It is a marine species that grows in the littoral zone, and therefore remains immersed in seawater for extended periods.

The original type specimens were collected by Göran Wahlenberg from northern Europe.

[3] Cécile Gueidan and Holger Thüs transferred the taxon to the newly circumscribed Wahlenbergiella in 2009 following molecular phylogenetic-directed revisions of the family Verrucariaceae; it is the type species of that genus.

[4] It is one of several marine Verrucariaceae lichens that have been investigated for use as possible bioindicators of coastal water pollution.