A new and distinct cultivar of Buxus semperviresn, `Polar`, found in a province of Sweden where the climate is cold (representing zone 4 of the Swedish Hardiness Map) that exhibits exceptional winter hardiness. `Polar` is further characterized by a dense, compact, and medium to broad growth habit and evergreen foliage with leaves that are broadly elliptic in shape, shiny in appearance, and dark green in color that exhibits no substantial change in coloration during the winter. `Polar` is well suited for topiary and for use in parks and gardens in cold climates, where other Boxwood cultivars are inappropriate.