Selaginella willdenowii is a species of vascular plant in the Selaginellaceae family. It is a spikemoss known by the common names Willdenow's spikemoss and peacock fern (a name shared with S. Uncinata) due to its iridescent blue leaves. Like other Selaginallales, it is fern ally and not a true fern.

Selaginella willdenowii is sometimes spelt incorrectly as Selaginella willdenovii.