People travelling to Scotland from Czech Republic and Jamaica now have to self-isolate for 14 days upon arrival.
The two countries were added to the UK quarantine list – along with Switzerland – on Thursday, with the change coming into effect from 4am on Saturday.
People arriving in Scotland from Switzerland were already required to self-isolate.
The decision was made because of a “significant rise” in the number of coronavirus cases there, the Scottish Government said.
Failure to comply with the requirement to quarantine can result in a fine of £480.
Justice secretary Humza Yousaf said the situation in countries “can change suddenly”, adding the importation of new Covid-19 cases from abroad “remains a significant risk to public health”.
He said: “We continue to closely monitor the situation in all parts of the world and base the decision we make on the scientific evidence available.
“Regular discussions continue to be held with the other three governments in the UK.
“Requiring travellers arriving from a non-exempt country to quarantine for 14 days on arrival, is vital to helping prevent transmission of the virus and to suppress it.”
Meanwhile, people arriving in the country from Cuba after 4am on Saturday no longer need to quarantine.
For a full list of countries on the quarantine list and those nations that are exempt, click here.