The 30-year-old will not recover in time from the fibular injury he sustained last week while playing for Bayern Munich against Werder Bremen.
Mane had been expected to miss at least Senegal's opening game of the World Cup against Netherlands on Monday, with manager Aliou Cisse naming the former Liverpool striker in his 26-man squad despite fitness concerns.
But Mane's injury is much more serious than first feared and has undergone surgery which rules him out completely from the World Cup.
A statement from Bayern Munich confirming Mane's unavailability for his national team read: "Sadio Mane underwent successful surgery in Innsbruck by Prof Christian Fink and Dr Andy Williams from London on Thursday evening.
"During the operation, a tendon was reattached to the head of his right fibula. The Bayern forward will therefore no longer be available to play for Senegal at the World Cup and will begin his rehab in Munich in the next few days."
The news comes as a serious blow for Senegal, who will also take on hosts Qatar and Ecuador in Group A.
Mane is Senegal's all-time top scorer with 34 goals from 93 caps.
He has scored two decisive penalties for the Teranga Lions this year; the first helping them win the Africa Cup of Nations for the first time against Egypt in February and the second against the same opponents sealing their place in Qatar.
