0727 GMT February 25, 2020
The number rose from 685,000 in 2000 to 20.9 million as of June 2017, according to UNAIDS, the Joint United Nations Program on HIV and AIDS, UPI reported.
Michel Sidibe, executive director of UNAIDS, said, "Many people do not remember that in 2000 there were only 90 people in South Africa on treatment.
"Today, South Africa has the biggest life-saving treatment program in the world, with more than four million people on treatment.
"This is the kind of acceleration we need to encourage, sustain and replicate."
The new report also said that because more people with HIV are receiving treatment, more of them are alive and well.
Research also shows that people with HIV who adhere to antiretroviral treatment are up to 97 percent less likely to transmit the AIDS-causing virus to others.
And as treatment has become more available to pregnant women, there has been a sharp drop in the number of children born with HIV.
However, a number of challenges remain, the report said.
One is to provide antiretroviral treatment to over 17 million people with HIV who currently aren't receiving it, including 919,000 children.
Another challenge is to make HIV prevention a public health priority again, particularly in nations with rising HIV infection rates.
In Eastern Europe and central Asia, for example, the rate of new infections has risen 60 percent since 2010 and AIDS-related deaths have increased 27 percent, according to the new report.