The airport has been mainly running business flights to Jersey
London Oxford Airport has begun its international scheduled flight service to Switzerland.
The airport in Kidlington, Oxfordshire, has been mainly running business flights to Jersey until now.
Its first flight to Geneva, which took off 1405 GMT on Saturday to arrive at 1700 local time (1600 GMT), marked the start of the service.
Swiss airline, Baboo, which has a fleet including three Embraer 190s, is operating the route's flights.
Baboo will also run a Saturday service departing from Geneva at 1220 local time (1120 GMT) to arrive at Oxford 1320 GMT.
London Oxford Airport's managing director Steve Jones said: "We are delighted to introduce Geneva as our first international scheduled service and see this as a major turning point in the future of the airport."