The airport was inaugurated by prime minister Narendra Modi last month.
The airline will operate direct flights on the Kolkata-Pakyong-Kolkata route daily under the Centre's regional connectivity scheme UDAN.
Prime Minister Narendra Modi on Monday inaugurated the Pakyong aerodrome, where commercial flight operations are set to start from October 4.
The Prime Minister described the Himalayan province as serene, splendid, enchanting and incredible and used the hashtag Incredible India -- a tagline for India tourism.
The greenfield airport at Pakyong, built at a cost of Rs 605.59 crore, will put landlocked Sikkim on the aviation map of the country.