Kask is an Estonian surname meaning "birch". Notable people with the surname include:
Aleksander Kask (1885–1950), Estonian politician Aleksander Kask (1902–1965), Estonian weightlifter Arnold Kask (1902–1994), Estonian linguist, philologist and professor Herman Kask (died 1918), Estonian politician Jana Kask (born 1991), Estonian singer Janne Kask, former singer of the Swedish band Brainpool
Oskar Kask (1898–1942), Estonian politician Peet Kask (born 1948), Estonian politician Rein Kask (born 1947), Estonian politician Risto Kask (born 1985), Estonian civil servant and politician Teet Kask (born 1968), Estonian ballet dancer and choreographer Tim Kask (1949–2025), American editor and writer Tõnis Kask (1929–2016), Estonian director
See also Kõiv, another Estonian surname meaning birch