The ban will go into effect in 90 days, according to the US Food and Drug Administration, which described the final rule - issued after several years of study and debate - as "historic."
"As cigarette smoking among those under 18 has fallen, the use of other nicotine products, including e-cigarettes, has taken a drastic leap," said Health and Human Services Secretary Sylvia Burwell.
"Today's announcement is an important step in the fight for a tobacco-free generation - it will help us catch up with changes in the marketplace, put into place rules that protect our kids and give adults information they need to make informed decisions."
The rule also requires manufacturers to get marketing approval for any products that came on the market after February 15, 2007, to show that their "products meet the applicable public health standard set forth in the law."
More From This Section
This review process "gives the agency the ability to evaluate important factors such as ingredients, product design and health risks, as well as their appeal to youth and non-users," said the FDA in a statement.
A preliminary rule was issued in 2014, resulting in more than 135,000 public comments, an FDA spokesman said.
About one in five Americans smokes, and the habit kills 480,000 people in the United States each year, according to health authorities.
Traditional cigarette smoking has declined in recent decades, but youths are increasingly turning to e-cigarettes, which are battery powered devices that heat a nicotine liquid - and flavored cigars.
E-cigarette use among high-schoolers rose from 1.5 per cent in 2011 to 16 per cent in 2015 - a more than 900 per cent increase - according to the US Centers for Disease Control and Prevention.
Another recent study, carried out by the FDA and the National Institutes of Health in 2013-2014, showed four out of five youths who use some form of tobacco also had tried a flavored tobacco product in the past month.