The service, in partnership with Etihad Airways, will be operated by a two-class Airbus 320 aircraft and will fly three-times a week from December 2, the airlines said.
Air Seychelles' new service brings the number of regional destinations served by the airline to five, along with Antananarivo, Dar es Salaam, Johannesburg and Mauritius.
"Our new Mumbai schedule has been purposely designed to offer business and leisure travellers from India convenient and direct access to the Seychelles islands, one of the world's most prestigious holiday destinations," Air Seychelles CEO Manoj Papa said.
Joel Morgan, Seychelles Minister for Home Affairs and Transport and Air Seychelles Board Chairman, said: "Air Seychelles is a key economic enabler for our islands and the launch of our service to Mumbai marks a significant and exciting new chapter for Air Seychelles.