The name Planina comes from the Slovene common noun planina, referring to a mountain without trees or to a grassy mountain area used for grazing livestock. The longer name Planina pod Mirno Goro means 'Planina below Mount Mirna'. The German name of the settlement, Stockendorf, is a compound of Stock 'stump' and Dorf 'village', referring to a settlement at a site where land was cleared by burning and the stumps were then grubbed out. The Gottschee German name Aobə is the dialect form of the standard German noun Alpe 'mountain pasture' and semantically corresponds to the Slovene name Planina.