Flights to the Indian city will initially operate three times a week, increasing to four times weekly in November.
The route is operated by Finnair’s Airbus A330, offering Business and Economy Class.
The carrier already flies daily to India’s capital, New Delhi.
Sakari Romu, Finnair’s General Manager for India, said: “We are very excited to start our operations from Mumbai.”
“Our three-weekly flights serve our customers not only in providing a connection to Finland but also to our network in the US and major European cities”.
Flights depart Helsinki at 17:55, arriving into Mumbai at 05:15 the following morning.
The return flight departs Mumbai at 07:10, arriving into Helsinki at 14:05.