De Canio, 50, has previously coached Udinese, Napoli, Reggina, Genoa and Siena - he replaces caretaker boss Mick Harford, who has left the club with immediate effect after turning down a new role in the backroom staff.
"I am very excited at this fantastic opportunity to join Queens Park Rangers," De Canio said.
"For me, it will be an honour to work for a club which is backed by Bernie Ecclestone and Flavio Briatore, two businessmen with an incredible track-record of success in sport and other fields.
"I would like to thank them and tell them I will not disappoint their expectations.
"I am fully committed to the project and I am looking forward to getting to work with the players in preparation for our forthcoming home fixture against Hull City on Saturday."