Is Rosemaling Swedish?

In simple terms, no. Rosemaling is a destinctly Norwegian form of decroative painting. Evolving in rural Norway, rosemaling flourished in the late 1600's through the mid-1800's. 

Norwegian rosemaling was popularized in the United States in the1960s through the 1980's, and because of this, the term is more familiar and mistakenly applied to Swedish folk painting. Sweden's folk painting goes by various, lesser known names, such as kurbitsmålning (or kurbits), dalmålning, and bonadsmålning. While the folk arts may appear to be similar, there are distinct differences in style, colors, subject matter, what it is painted on, and designs can be very different from that of Norwegian rosemaling. 

Go here for more on the History of Rosemaling.

Vesterheim Norwegian-American Museum has a great resource for: What is Rosemaling.