Henry Merrill was an American merchant and pioneer of the U.S. state of Wisconsin. He was a member of the first session of the Wisconsin State Senate in 1848. His former home in Portage, Wisconsin, is listed on the National Register of Historic Places. Late in life, he wrote an essay of pioneer life in Wisconsin for the Wisconsin Historical Society.

The First Wisconsin Legislature convened from June 5, 1848, to August 21, 1848, in regular session. Members of the Assembly and Senate were elected after an election on February 1, 1848, that ratified the proposed state constitution.