Tasmanian Small Business Council chief executive Robert Mallett also criticised philanthropist and businessman Andrew Forrest's Minderoo Foundation for supporting the move.

"Once again the do-gooders from the mainland are trying to use Tasmania as some sort of social experiment laboratory," Mr Mallett said.

"The proposal to increase the legal smoking age to 21 will be a kick in the guts to small business and cost jobs in regional Tasmania, without doing anything to actually reduce smoking rates.

"Tobacco sales make a significant contribution to the profitability of small retailers and this change would cut a chunk out of their business, negatively affecting jobs, for no tangible health gain."

Under legislation introduced by Independent member for Windermere Ivan Dean the legal age for Tasmanians to buy tobacco products would be lifted from 18 to 21`incrementally over three years.

It would be an offence for a retailer to sell tobacco products to people aged under 21 and for a person to provide false proof of age.

Mr Mallett said he believed a high proportion of people started smoking before they turned 18 and "you'd be a fool to think that raising the legal age to 21 is somehow going to magically change this".

"At the age of 18 you are an adult - you can vote, drink, go to war for your country, you should be able to legally smoke too, if you so choose," he said.

"The anti-tobacco lobby have been quick to seize on statistics to demonstrate the number of people taking up tobacco use between the ages of 18-21 however, they fail to include statistics of people taking it up when they are under the age of 18 and being supplied by family and friends. In itself, this makes a mockery of their arguments for change."

Quit Tasmania director Abby Smith said Quit supported Mr Dean's legislation.

"We welcome the testing of new approaches to reduce smoking rates, particularly those that are feasible and broadly acceptable to our community," Ms Smith said.

"But we can't lose sight of proven tobacco control measures to reduce smoking rates such as continuing investment in hard-hitting mass media campaigns, increasing tobacco tax excise, expanding smoke-free areas and providing best practice stop smoking support like Quitline 13 7848.

"Any new approaches need to be undertaken as part of a comprehensive tobacco control strategy. "

Ms Smith said while she had no data on the effects of increasing the smoking age from 16 to 18 ,data showed that fewer young Tasmanians were smoking.

"The last Australian Secondary Students' Alcohol and Drug (ASSAD) survey in 2014 found that 77% of Tasmanian teens had never smoked," she said.

"The next 2017 ASSAD survey results will be released later this year and we expect to see a further increase in the number of teens who have never smoked.

About 70,500 Tasmanians smoke and Tasmania has the second highest smoking rate at 17.6 per cent, second to the Northern Territory.

More than 22 per cent of Tasmanian smokers are aged 18-24 years.