Kar de Mumma (August 14, 1904 in Stockholm – July 7, 1997 in Stockholm), birth name Erik Harald Zetterström, was a Swedish humorous writer and playwright. His pen name can be read as Car da Mon in Swedish.
In the 1920s and 30s, he wrote many of the most appreciated Swedish revues. 1956–1978, the revues he wrote for Folkan (Folk-theater) in Stockholm (among them the Kar de Mumma revue) became an institution on the Swedish theatre scene.
He was among the most appreciated Swedish humor columnists, writing for Svenska Dagbladet from 1922 until the mid-1990s. For thirty years he would publish a book with lighthearted columns, memories and thoughts in the fall.