No country in the world is using leaded petrol for cars and lorries, the UN Environment Programme has announced.
The toxic fuel has contaminated air, soil and water for almost a century.
It can cause heart disease, cancer and stroke, and has been linked to problems with brain development in children.
Most high-income countries had banned the fuel by the 1980s, but it was only in July that Algeria ran out.
UN Secretary-General António Guterres called the eradication of leaded petrol an “international success story”.
“Ending the use of leaded petrol will prevent more than one million premature deaths each year from heart disease, strokes and cancer, and it will protect children whose IQs are damaged by exposure to lead,” he said.
Lead started being added to petrol in the early 1920s in order to improve engine performance.
The alarm was raised as early as 1924, when five workers were declared dead and dozens more hospitalised after suffering convulsions at a refinery run by the US oil giant Standard Oil.
But despite this, lead continued to be added to all petrol globally until the 1970s.
Wealthier countries then started phasing out its use, until early 2000s there were still 86 nations using leaded petrol.
North Korea, Myanmar and Afghanistan stopped selling leaded petrol by 2016, leaving only a handful of countries, including Iraq, Yemen and Algeria, still providing the toxic fuel in the latter half of the last decade.