Less than a third of South Africans have completed matric, according to the Census 2011 results.
The results reveal 28.4 percent of the population completed grade 12, compared to 20.4 percent in 2001.
The percentage of people who had some form of secondary education grew from 30.2 percent in 2001 to 33.8 percent in 2011.
A further breakdown shows 8.6 percent have not had any schooling at all, compared to 17.9 percent in 2001.
"There is a relatively high percentage of persons aged 20 years and older with no schooling in Limpopo (17.3 percent), followed by Mpumalanga (14 percent)," the census document says.
The Western Cape has the lowest number of persons aged 20 and higher who have not had any form of education (2.7 percent).
The number of South Africans with a post-matric qualification is 12.1 percent, an increase from 9.1 percent in 2001.
"The province with the highest proportion of the population aged 20 years or more with post-grade 12 qualifications is Gauteng (18 percent), followed by the Western Cape (14.4 percent)," the document shows.