The team said in a release that Spagnuolo would be introduced at a news conference tomorrow.
The St. Louis Post-Dispatch was the first to report the hiring and said Spagnuolo would be paid just under $12 million.
Spagnuolo replaces Jim Haslett and takes over a team that finished 2-14.
"There's just a toughness about him," general manager Billy Devaney said. "He represented what we were looking for."
Spagnuolo, 49, was one of five finalists for the job, along with Haslett, Dallas Cowboys offensive coordinator Jason Garrett, and defensive coordinators Rex Ryan of the Ravens and Leslie Frazier of the Minnesota Vikings.
Morris takes over a team that won three division titles under his predecessor but hasn't won a playoff game since capturing the franchise's only NFL title in January 2003. The Gruden era ended with four consecutive losses that denied the Buccaneers a playoff spot.
Morris, 32, has no previous head coaching experience. Tampa Bay promoted him to defensive coordinator Christmas Day.
Mark Dominik, who has been with the team since 1995, takes over as general manager, replacing Bruce Allen, who also was fired Friday.
The four-time Pro Bowl defensive end has decided he won't sign a long-term deal with Carolina when he becomes an unrestricted free agent Feb. 26.
Carey, who first told ESPN.com of Peppers' decision, said Peppers wants to play in a 3-4 defense. The Panthers use a 4-3 alignment.
Miami Dade County Jail spokeswoman Janelle Hall said Vilma was arrested Friday afternoon.
Raiders: : Assistant coach John Fassel, a former Ravens special teams assistant and the son of former Giants coach Jim Fassel, was promoted to special teams coordinator.