Caldwell, who had been one of Dungy's assistants since 2001, was had been anointed Dungy's successor last January and it came to pass when he retired Monday.
"From this day forward I'll thrive in the quality environment (owner) Jim Irsay, (President) Bill Polian and Tony Dungy have created," Caldwell said. "I want to thank each one of them for the confidence they have placed in me and what a privilege it is to direct one of the great organizations in the National Football League."
Caldwell served as quarterbacks coach for the first three seasons with Indianapolis before becoming assistant head coach in 2005.
"I want to thank Tony for what he has done for me over the years," Caldwell said. "He set a great example for all of us in this profession."
Caldwell's lone head-coaching experience was ast Wake Forest from 1993-2000, where he had a 26-63 record with one winning season and one bowl appearance. He was also a college assistant at Iowa, Southern Illinois, Northwestern, Colorado, Louisville and Penn State.