Kossak is the surname of 4 generations of notable Polish painters, writers and poets, descending from the historical painter Juliusz Kossak. Notable people with this surname include:

• Progenitor, Juliusz Kossak (1824–99), Polish painter from the partitions period
• Tadeusz Kossak (1857–1935), Polish army officer and freedom fighter
• Wojciech Kossak (1857–1942), painter, son of Juliusz Kossak
• Jerzy Kossak (1886–1955), painter, son of Wojciech Kossak, grandson of Juliusz Kossak
• Zofia Kossak-Szczucka (1889–1968), novelist, daughter of Wojciech Kossak's twin brother Tadeusz Kossak, granddaughter of Juliusz Kossak
• Maria Pawlikowska-Jasnorzewska née Kossak (1891–1945), poet, second daughter of Wojciech Kossak, granddaughter of Juliusz Kossak
• Magdalena Samozwaniec née Kossak (1894–1972), writer, third daughter of Wojciech Kossak, granddaughter of Juliusz Kossak
• Karol Kossak [pl] (1896–1975), painter and illustrator
• Zenon Kossak (1907–1939), Ukrainian activist
• Gloria Kossak (1941–1991), painter and poet, daughter of Wojciech Kossak's son, Jerzy Kossak (1886–1955), sister of Simona Kossak
• Simona Kossak (1943-2007), biologist, ecologist, and professor of forest sciences, daughter of Jerzy Kossak, sister of Gloria Kossak