Any travellers who arrived in Australia after March 14 who then enter Tasmania will be required to quarantine for 14 days in a state-controlled facility.
This comes after an announcement by Prime Minister Scott Morrison all international arrivals into Australia after 11.59pm on Saturday will be quarantined in hotels at their port of arrival.
Coronavirus: All the latest updates on COVID-19 for Tasmania
If a Tasmanian arrives in Melbourne or Sydney, they will be quarantined there for 14 days before being allowed to return to Tasmania.
Premier Peter Gutwein said people who had been quarantined for 14 days at a mainland port would be quarantined for a further 14 days after entering Tasmania.
Mr Gutwein said any non-essential travellers who arrived in Australia after March 14 who then enter Tasmania would also have to be quarantined for 14 days in a state-controlled facility.
"If you travelled from overseas [and] were travelling or holidaying in one of the other states you will be going into a 14 day self-isolation period in a government facility," Mr Gutwein said.
Three state-controlled facilities will be established in hotels, one each in the North, North-West and the South of Tasmania.
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Mr Gutwein said the government was considering if state-controlled quarantine would be applied to other non-essential travellers, for example visitors coming from Victoria or New South Wales.
"We are looking into if they will spend their self-isolation period in government facilities. I will have more to say on that in coming days," he said.
Congregating in groups of 10 or more people will also be an offence from 6pm on Friday.
"What we don't want to see, with our pubs and hotels shut, is people congregating and putting themselves at high risk," Mr Gutwein said.
"It will be an offence from 6pm tonight should people take no heed of this direction. The consequence is a fine up to $16,800."
Mr Gutwein said going to the beach this weekend was not an offence "not unless you take nine mates with you".
Larger families who have more than 10 people living in one residence will be excepted.