We describe Tenuibiotus yeliseii sp. nov., a new tardigrade species from Svalbard, using morphological and morphometric analyses conducted with the use of light and scanning electron microscopy, as well as genetic analyses based on four molecular markers (three nuclear, 18S rRNA, 28S rRNA, ITS-2, and one mitochondrial, COI). A phylogenetic analysis of the genus Tenuibiotus Pilato et Lisi, 2011 is conducted using new data. In addition, the taxonomic significance of gibbosities on legs IV as a key character for species identification in Tenuibiotus is discussed. A key to the species of Tenuibiotus is proposed.