Crassula montana subsp. borealis, a new, dwarf, cliff-hugging succulent, is described from the quartzitic sandstone cliffs along the Skaaprivierspoort (N.W. of Springbok). It has also been found on the upper slopes of the saw-edged peaks of the Rosyntjieberg (Richtersveld) in the Northern Cape and is known from only these two populations. The cup-shaped rosettes of broadly ovate leaves, which are pitted, immediately distinguish it from C. montana subsp. montana and C. pseudohemisphaerica.