The deal includes no player option, Torrel Harris said.
Harris met with Sixers general manager Elton Brand and ownership on Sunday at the Sixers practice facility, and quickly reached an agreement on the massive new deal.
"I want to be somewhere that I can call home. Finally, I can do that now: I'm a Philadelphia 76er," said Harris.
Harris, 26, has been the central focus of the Sixers free agent recruitment. The Sixers traded two future first-round picks and 2018 first-round pick Landry Shamet as part of a package to acquire Harris in February from theLA Clippers.
Harris has played with Milwaukee, Orlando, Detroit, the Clippers and 76ers in his eight-season NBA career.