The Bristow-operated offshore helicopter, an Airbus EC225, alerted the airport control tower at around 10.50am after a warning light was triggered.
It landed safely at around 11am with all 18 passengers and two crew reported as being safe and well.
The airport fire services, ambulance crews and police were all scrambled, while the Sumburgh-based Coastguard rescue helicopter was put on standby.
A Bristow spokesman said: “Bristow Helicopters Ltd can confirm that one of its Airbus EC225 helicopters was diverted to Sumburgh Airport today at approximately 10.50am after a caution light illuminated in the cockpit.
“The aircraft was undertaking a routine crew change flight to an offshore installation and had 18 passengers and two crew on-board at the time.
“The aircraft landed safely at Sumburgh Airport at approximately 11am and is currently undergoing a fault diagnosis to establish the required maintenance actions.
“The landing itself was uneventful but Sumburgh Airport mobilised the emergency services as a matter of routine.”
He added: “Flight safety is Bristow’s first priority and we will always investigate prior to further flight.
A spokesman for Highlands and Islands Airports, who operate Sumburgh Airport, said: “There was an incident involving a Bristow helicopter at Sumburgh Airport this morning.
“The aircraft landed safely and the incident was quickly stood down. In line with standard procedures, HIAL’s airport fire service were on standby but were not required.”
Last year, four offshore workers died when a Super Puma AS332 L2 helicopter, crashed in the sea just off the Sumburgh coast at Garth’s Ness.
Sarah Darnley, 45, from Elgin, Duncan Munro, 46, from Bishop Auckland, and George Allison, 57, from Winchester, all drown, while Gary McCrossan, 59, from Inverness, suffered heart failure in the August disaster.
In October 2012 all 19 people on board a Super Puma EC225 were rescued safely after it put down in the sea off Shetland. The incident was caused by a cracked shaft in the main gearbox.
In May 2012 all 14 people on board a Super Puma EC225 were rescued when it came down about 30 miles off the coast of Aberdeen during a flight to an oil rig.
In April 2009 all 14 passengers and two crew on board a Super Puma AS332L2 lost their lives after it came down in the North Sea. Eight of the victims came from the north east of Scotland, seven from the rest of the UK, and one from Latvia.
And in February 2009 a Super Puma EC225 ditched in fog a short distance from a BP oil platform in the ETAP field, 125 miles east of Aberdeen. All 18 people on board survived. Crew error and a faulty alert system were blamed.