Travellers coming to Scotland will need to show proof of a negative test from Friday.
Speaking at the coronavirus briefing in Edinburgh, the First Minister said those arriving in the country after 4am on Friday will need evidence from the past three days that they have tested negative.
Nicola Sturgeon stressed that the test will need to be “highly reliable”, most likely meaning it will have to be a PCR test.
Young children may be exempt from the requirement.
She said: “I want to be very clear here, this requirement for testing before entry to the country is seen not as a substitute for the protections and mitigations in place, but as an addition to those.
“Testing before entry to the country is not a magic solution to the risk of cases being imported, so it will reinforce rather than replace our current travel restrictions.”
Those travelling from countries not on the quarantine exemption list will still need to self-isolate on arrival.
Spot checks will be carried out at airports by Border Force, with officers able to fine passengers without a negative test £480.
Non-essential travel in and out of Scotland is currently illegal under coronavirus-fighting laws.