The Pistons have not disclosed terms of the deal, but league sources told ESPN that Casey agreed to a five-year contract.
The Pistons stayed aggressive in pursuit of Casey and closed on a deal to land the franchise's primary coaching target. Owner Tom Gores and senior adviser Ed Stefanski sold Casey with an aggressive contractual commitment and a case that together, they could make the Pistons a perennial playoff team in the Eastern Conference.
Detroit is working to reshape its franchise, hiring Stefanski and Casey to replace former president and coach Stan Van Gundy as the centralized leadership of the organization. The Pistons are committed to building the roster around All-Star forward Blake Griffin, whom they acquired in a February trade from the LA Clippers.
Casey said on ESPN Radio's Stephen A. Smith Show that keeping Griffin healthy needs to be one of the Pistons' top priorities. He also said he plans to expand Griffin's responsibilities.
"We're going to empower him to expand his game, a lot like DeMar DeRozan in Toronto," he said. "Expand his game out to the 3-point line, have some point-forward responsibilities with the basketball out on the floor bringing it down. Because he's more than just a back-down, post-up player."
Casey said on ESPN Radio that he wasn't sure if he needed to sit out a year after being fired by Toronto, but Gores and Stefanski "made a really compelling case on how we could do it together and really convinced me that this was the right place to be."
"They have a good team, they have a good roster and a very dynamic owner in Tom Gores, who is doing a lot of things for the city of Detroit," Casey said. "It's a little bit more than just coaching basketball ... that appealed to me also and to my family. Doing a lot of stuff in the community, rebuilding downtown, helping out Flint in their water situation -- so just a lot more things involved, more than just basketball."
Casey, 61, the presumptive NBA coach of the year, led the Raptors to a franchise-record 59-win season, the No. 1 seed in the East and a berth in the conference semifinals.
But after a second consecutive series sweep to the Cleveland Cavaliers, Casey was fired by the Raptors. In seven seasons, Casey reached the playoffs five times -- including the franchise's first conference finals -- and won 50-plus regular-season games in each of his final three seasons.
"Dwane is one of the most successful and highly respected coaches in our league," Gores said in a statement released by the team. "He's a great communicator and a leader who will connect with our players and accelerate their growth. Having spent many hours with Dwane over the last few weeks, I'm confident he is the right person to get us to the next level.
"In our meetings he displayed great insight into what this roster can accomplish, and great passion about our city and the team's role in bringing people together. He's an outstanding man with impressive character. He embodies our culture and will be a great representative for our franchise."