Don Alonzo Joshua Upham (May 1, 1809 – July 19, 1877) was an American lawyer, Democratic politician, and Wisconsin pioneer. He served as the 4th Mayor of Milwaukee and was the Democratic nominee for Governor of Wisconsin in the 1851 election. He also served as President of the first Wisconsin Constitutional Convention and was United States Attorney for Wisconsin during the presidency of James Buchanan. His name was often abbreviated as D. A. J. Upham in historical documents.