In 2022, about one in five adults around the world were smokers or consumed other tobacco products, compared to one in every three in 2000, the UN health agency said.
A fresh report looking at trends in the prevalence of tobacco use between 2000 and 2030 showed that 150 countries were successfully reducing tobacco use, the WHO said.
But while smoking rates are declining in most countries, the WHO warned that tobacco-related deaths were expected to remain high for years to come.
Currently, tobacco use is still estimated to kill more than eight million people each year, including an estimated 1.3 million non-smokers who are exposed to second-hand smoke, WHO statistics show.
"Countries implementing strong tobacco control measures can expect to wait about 30 years between turning the prevalence rate from increasing to decreasing and seeing an associated turnaround in the number of deaths due to tobacco," Tuesday's report said.
'No time for complacency'
And while the number of smokers has steadily shrunk, the WHO said the world was set to miss its goal of a 30-percent drop in tobacco use between 2010 and 2025.
Fifty-six countries around the world are expected to hit that target, including Brazil, which has already slashed tobacco use by 35 percent since 2010.
Six countries have meanwhile seen tobacco use rise since 2010 -- the Republic of Congo, Egypt, Indonesia, Jordan, Moldova and Oman.
Overall, the world is on track to shrink tobacco use by a quarter over the 15-year period to 2025, the report said.
FILE - A woman holds a pack of cigarettes in a tobacco shop at the Vallecas neighborhood, in Madrid,Spain March 13, 2020.
While celebrating the advances made, the WHO warned that the tobacco industry was intent on rolling them back.
"Good progress has been made in tobacco control in recent years but there is no time for complacency," said Ruediger Krech, director of the WHO's health promotion department.
"I'm astounded at the depths the tobacco industry will go to pursue profits at the expense of countless lives," he said.
"We see that the minute a government thinks they have won the fight against tobacco, the tobacco industry seizes the opportunity to manipulate health policies and sell their deadly products."
Fight 'tobacco industry interference'
The WHO urged all countries to maintain and strengthen control policies and to fight "tobacco industry interference."
A particular focus, it said, should be on gathering better data on tobacco use among adolescents, especially for newer so-called smokeless products.
The report said that on average, around 10 percent of 13- to 15-year-olds globally use one or more types of tobacco.
That amounts to at least 37 million adolescents, including at least 12 million who use new smokeless tobacco products.
FILE - Cigarette butts sit in an ashtray on March 28, 2019, in New York.
But the report stressed these numbers were an underestimate since more than 70 countries provide no data.
This was worrying because "countries need these data to counter tobacco and associated industries' claims that adolescents are not being targeted as new clients", it said.
The available data suggests the industry attempts to undermine countries' efforts to dissuade young people from using tobacco products.
"Young people are still reporting regular use of the products, easy access to purchasing them and low concerns about becoming addicted," the report said.
"Gathering data from adolescents on their knowledge, attitudes and practices is the most powerful way to combat the industry and shape effective policies that prevent initiation of tobacco use."