Singapore Airlines will fly to Adelaide twice a day, three days a week, boosting tourists this summer.

It will be the first time Adelaide Airport will have more than one flight a day from the same international airline, taking the airport's weekly tally of international services to 36.

In 2007, Singapore Airlines became the first international airline to operate daily flights through Adelaide. Since then Cathay Pacific has operated services from Hong Kong seven days a week, and Malaysia Airlines from Kuala Lumpur six days a week.

Yesterday Singapore Airlines confirmed it would have two flights a day on Mondays, Tuesdays and Saturdays from December 9 to January 31. The move follows lobbying by the South Australian Tourism Commission for additional flights.

For the three new flights, Singapore Airlines will use a wide-body Boeing 777-200 aircraft of 12 business-class and 276 economy seats. It means an additional 864 international seats into Adelaide each week.

SA Tourism Commission destination development manager Nick Jones said this was good news for South Australia.

"Singapore Airlines' decision demonstrates confidence in the market for SA tourism during the peak summer period," he said.

"There is much competition in the region for additional seasonal services and the airline has shown great faith in the SA market."

Mr Jones said SA was set to gain from the key international tourism markets of Europe, Singapore and China through the extra flights and the airline's good flight connections and marketing.

Singapore Airlines' SA manager, Andrew Soo, said 10 flights a week to Adelaide underlined the city's importance to the airline.

The additional flights will arrive at Adelaide Airport at 6:05 a.m. and depart at 7:20 a.m., arriving in Singapore at noon, Singapore time.

Mr Soo said SA travellers on the new flights would have a greater choice of connections to destinations such as London and Frankfurt for same-day travel. Singapore Airlines will continue to operate an Airbus A330-300 aircraft on its usual daily flights to and from Adelaide.

Cathay Pacific announced last week it would launch non-stop services from Adelaide to Hong Kong three days a week from November.

The other flights will continue to include a stopover in Melbourne.