South Africans are on average living up to 61.2 years compared to 52.2 years some 10 years ago.
"For 2014 life expectancy at birth is estimated at 59.1 years for males and 63.1 years for females," said Statistics South Africa (Stats SA) in an annual demographics report.
"This increase in life expectancy at birth is expected to continue."
With the mass rollout of ARVs, the number of HIV-related death declined to 31.1 percent this year from 50.8 in 2005.
Under the former presidency of Thabo Mbeki, South Africa refused to roll out state sponsored AIDS drugs. The treatment was so expensive that it was only accessible to the well-heeled.
But now the country now has the largest anti-retroviral programme in the world, serving 2.5 million people -- more than double the number three years ago.
It has been hailed as a model for HIV treatment.
Stats SA estimates that 10.2 percent of the 54 million South Africans is HIV-positive.
A separate study conducted in 2012 suggested the HIV/AIDS prevalence rate was 12.3 percent of the population or 6.4 million people.
The statistics agency also said the population of Africa's most developed country will reach 54 million this year, a increase of one million over the past year.
Of these 54 million, 80.2 percent will be blacks, 8.8 percent of mixed race, 8.4 percent whites and 2.5 Indians.
Stats SA estimated 2.76 million Africans and nearly 100,000 Asians will have migrated to Africa's second-largest economy between 2001 and 2015, while 340,000 white South Africans would have emigrated from the country over the same period.