All three cases are in Southern Tasmania and are people who travelled overseas.

A woman in her 40s travelled from the United Kingdom and two men in their 40s who travelled together had been through several European countries.

Public Health director Mark Veitch said all three cases arrived in Tasmania on March 15 and self-isolated after arriving.

"There's virtually no risk to the public from these three cases because there was no community exposure from these three people in Tasmania," Dr Veitch said.

"They were tested on Tuesday and results came through on Wednesday."

All three are in a stable condition and are being assessed at their homes by clinicians.

"All the people in Tasmania have had mild to moderate symptoms," Dr Veitch said.

But Public Health said it would be following up with people on two flights into the state who were seated in the two rows in front, the same row, and two rows behind the new cases.

There have been 10 confirmed cases of coronavirus in Tasmania. Three have recovered.

As of Wednesday night, a total of 707 tests have been conducted.