Two Coastguard helicopters and a mountain rescue team were called out to search for the aircraft after an emergency beacon was activated near Oban shortly after 11am.
The aircraft was found at Ben Lora near the village of Benderloch, near Oban airport.
The injured people were airlifted separately to Glasgow airport where they were transferred to the Royal Alexandra Hospital in Paisley and the Queen Elizabeth University Hospital in Glasgow.
Their condition is not yet known.
A spokeswoman for the Maritime and Coastguard Agency said that the UK Aeronautical Rescue Coordination Centre received a call with reports of a light aircraft crash near Ben More.
“This report was followed shortly by a report from Rescue Co-ordination Centre Germany of an aircraft emergency locator transmitter activated at Ben Lora, Scotland - 35 miles to the west of the initial incident reported.
“Two UK Coastguard helicopters were immediately scrambled by the ARCC and sent to the two locations. UK Coastguard helicopter based at Inverness was sent to Ben More and UK Coastguard helicopter based at Prestwick was sent to Ben Lora.
“The UK Coastguard Prestwick helicopter located the crashed aircraft on a mountain, with the helicopter from Inverness arriving on the scene 15 minutes later.”
RAF Lossiemouth mountain rescue team were making their way to the scene but have now been stood down.
Emergency services remain at the scene of the crash.