Roman Denissen was Mayor of Green Bay, Wisconsin.
Denissen was born on July 13, 1918 in Bellevue, Wisconsin. His father, Matt, was Supervisor of Bellevue. Denissen would marry Ursula Carmody in 1939. They would have one son before her death in 1983. In 1984, he married Agnes (Johnson) Le Clair. She died in 2003. Denissen died on January 21, 2008. He was Roman Catholic.
Denissen was elected to the City Council of Green Bay in 1952. He was named President of the Council in 1955. He ran unsuccessfully for Mayor against Otto Rachals in 1957. Two years later, he ran against Rachals again, this time winning. He served as Mayor until 1965, when he was defeated for re-election by Donald Tilleman.