The carrier, which already serves the New Delhi-Helsinki route seven days a week, would operate five flights a week to India's financial capital.
The first flight from Helsinki-Mumbai will depart from the Finnish capital at 2000 hrs on Tuesday and arrive at 0610 hrs in Mumbai on Wednesday. The first Mumbai-Helsinki flight will depart from Mumbai at 0815 hrs and reach the destination in eight hours.
Finnair commenced its operations to New Delhi on October 31 last year.
The new route opens huge possibility for tourist traffic between Europe and India, Finnair director (Indian subcontinent) Taina Tornstrom said in a statement.
"Apart from Mumbai, this flight would be very convenient for passengers from neighboring cities like Pune and Ahmedabad. The Mumbai route also gives Finnair more onward connections to destinations all over India.
"Finnair is strengthening its partnerships with Indian air carriers to make these connections as smooth as possible," Tornstrom said.