Karl Grönsfelder (18 January 1882 - 20 February 1964) was a Bavarian political activist and politician (KPD).When the Communist party was briefly banned in 1923/24, his activism earned him a period in "protective custody" in June 1924.
A longer period of detention followed the Nazi take-over in 1933.
After 1945 Grönsfelder returned to political activism, despite being marginalised and expelled (not for the first time) from the Communist Party in 1949.