Tempskya is an extinct genus of tree fern that lived during the Cretaceous period. Fossils have been found across both the Northern and Southern hemispheres. The growth habit of Tempskaya was unlike that of any living fern or any other living plant, consisting of multiple conjoined dichotomous branching stems enmeshed within roots that formed a "false trunk".

The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae, Dicksoniaceae, Metaxyaceae, and Cibotiaceae. It is estimated that Cyatheales originated in the early Jurassic, and is the third group of ferns known to have given rise to tree-like forms. The others are the extinct Tempskya of uncertain position, and Osmundales where the extinct Guaireaceae and some members of Osmundaceae also grew into trees. In addition there were the Psaroniaceae and Tietea in the Marattiales, which is the sister group to most living ferns including Cyatheales.