The study, which was conducted with the US National Cancer Institute and released on Tuesday, found that more than 80 percent of these deaths occur in low and middle-income countries.
Smoking also costs the global economy more than a trillion dollars annually.
Those costs far outweigh global revenues from tobacco taxes, which the WHO estimated at about $269bn in 2013-2014.
"It is responsible for over $1 trillion in healthcare costs and lost productivity each year," said the study, peer-reviewed by more than 70 scientific experts.
The economic costs are expected to continue to rise, and although governments have the tools to reduce tobacco use and associated deaths, most have fallen far short of using those tools effectively.
Jeremias Paul, the head of WHO's Tobacco Control Economics Unit, told Al Jazeera that the most effective form of reducing smoking is increasing the tax on tobacco.
"It is also the most underutilised method for tobacco control," he said.
Taxing tobacco will have the most effect in low-income areas because money is hard to come by. Right now tobacco is really cheap in those areas, Paul explained.
Tobacco taxes could also be used to fund more expensive interventions such as anti-tobacco mass media campaigns and support for cessation services and treatments, it said.
Governments spent less than $1bn on tobacco control in 2013-2014, according to a WHO estimate.
Furthermore, tobacco use accounts for a significant share of the health disparities between the rich and poor. These disparities are exacerbated by a lack of access to healthcare.
Although smoking prevalence is falling among the global population, the total number of smokers worldwide is rising.
China alone will suffer two million deaths a year by 2030, unless actions is taken to reduce the number of smokers.
An anti-smoking campaign will soon be launched in the country.
In Beijing, where it is illegal to smoke inside public buildings, a group of volunteers has the authority to hunt for smokers in these public spaces and fines them when they are caught in the act.