William Henry Carman Folsom (June 22, 1817 – December 17, 1900) was a businessman and politician in Minnesota.

Born in New Brunswick, Canada, he later emigrated to the United States and settled in Maine.

[1] Folsom was also involved in state's early political development, attending the Republican constitutional convention in 1857 and serving four different terms in the Minnesota House of Representatives and Minnesota State Senate between 1857 and 1877.

He was credited as helping organize the first district court in the state and was also part of the committee which developed the first official Seal of Minnesota in 1858.

Folsom House in Prairie du Chien, Wisconsin, is listed on the National Register of Historic Places.