Mortimer Melville Jackson (March 5, 1809 – October 13, 1889) was an American lawyer, judge, and diplomat.

He was a justice of the original Wisconsin Supreme Court from 1848 through 1853 and was later a United States consul general in Canada for twenty years.

In 1838, Jackson moved to Milwaukee,[1] and then in 1839, to Mineral Point, Wisconsin Territory,[1] where he practiced law, involving the lead-mining industry.

In 1861, President Abraham Lincoln appointed Jackson United States consul general in Halifax, Canada.

[2] As consul general, he was instrumental in the seizure of about $3,000,000 worth of Confederate property during the American Civil War (about $49,000,000 in inflation-adjusted dollars).