Matthew P. Denn is an American lawyer and politician from New Castle County, Delaware. He served as the 45th attorney general of Delaware from 2015 until 2019. Denn previously served as the 25th lieutenant governor of Delaware from 2009 to 2015, and was the Insurance Commissioner of Delaware from 2005 to 2009. After leaving public office, Denn joined the global law firm DLA Piper as Managing Partner of the firm's Wilmington office.

The lieutenant governor of Delaware is the second ranking executive officer of the U.S. state of Delaware. Lieutenant governors are elected for a term of four years in the same general election as the U.S. president and take office the following January.