Sixty-one people who arrived in Amsterdam on two flights from South Africa have tested positive for Covid-19, Dutch officials say.
They have been placed in isolation at a hotel near Schiphol airport.
They were among some 600 passengers held for several hours after arrival while they were tested for the virus.
Dutch health authorities said Omicron, labelled on Friday as a variant of concern, was “probably found in a number of people” who tested positive.
Anyone who tested positive would have to quarantine at a hotel for seven days if showing symptoms and for five days if not, it added.
Those that tested negative have been asked to isolate at home for five days and take further tests, while those in transit are allowed to continue their journeys.
Other European countries, including the UK and Germany, have confirmed cases of the Omicron variant.
The variant was first reported to the World Health Organization from South Africa on Wednesday, with early evidence suggesting it has a higher re-infection risk.
Many countries around the world have restricted travel from the southern African region.
Meanwhile, the Netherlands is one of several European countries struggling to contain record numbers of infections.
A partial lockdown will be extended on Sunday, with all hospitality and cultural venues forced to close between 5:00pm and 05:00am, at least until 19 December.