| Theodore Dieckmann | |
| Order: | 31st |
| Mayor of Sheboygan, Wisconsin | |
| Term Start: | April 1905 |
| Term End: | April 1915 |
| Predecessor: | Fred A. Dennett |
| Successor: | Otto B. Joerns |
| State Assembly1: | Wisconsin |
| District1: | Sheboygan 1st |
| Term Start1: | January 2, 1893 |
| Term End1: | January 7, 1895 |
| Predecessor1: | Dennis T. Phalen |
| Successor1: | Christian Ackerman |
| Birth Date: | 6 November 1853 |
| Birth Place: | New York, New York, U.S. |
| Death Place: | Sheboygan, Wisconsin, U.S. |
| Restingplace: | Wildwood Cemetery, Sheboygan |
| Occupation: | Merchant |
Theodore Dieckmann (November 6, 1853October 6, 1919) was an American businessman and Democratic politician. He was the 31st mayor of Sheboygan, Wisconsin, (1905 - 1915) and represented Sheboygan for one term (1893) in the Wisconsin State Assembly.
Dieckmann was born in New York City in 1853. As a child, he moved to Sheboygan, Wisconsin, with his parents in 1858. Dieckmann owned a jewelry business in Sheboygan, Wisconsin. He served on the Sheboygan Common Council and was mayor of the city. In 1893, Dieckmann served in the Wisconsin State Assembly and was a Democrat. Dieckmann died at his home in Sheboygan, Wisconsin.[1] [2]