The South Korean tech giant said it reached the number 39 days after it began selling the phones in the country.
This makes the foldables its third-fastest set of smartphones to reach a million units, after Galaxy Note 10 and Galaxy S8, Samsung said.
A total of 270,000 units of Galaxy Z Fold 3 and Galaxy Z Flip 3 were sold on the first day of sales, the company's highest first-day sales for smartphones to date in South Korea, it added.
Demand for the models was much higher than the company anticipated, Samsung said, with the company crediting the popularity to its online marketing campaigns and increased durability and usability of the devices compared to predecessors.
According to Samsung, the Galaxy Z Flip 3 accounted for around 70% of the sales from its latest foldable series. The model, offered in seven colours, was especially popular among female consumers and millennials, the company said.
For the Galaxy Z Fold 3, the black colour was the most popular, while the 512GB model accounted for 40% of the sales in the model, Samsung added.
At the same time, the company has also been offering a return program where those who buy a Galaxy Z Fold 3 and a Galaxy Z Flip 3 can return older phones, including iPhones for a value higher than the market price.
- Samsung raises spending in logic chip businesses to $151 billion
- Samsung pushes vRAN to take larger role in 5G networks
- Samsung's Galaxy Unpacked event in August: What to expect and how to watch
- The best Samsung phones in 2021: Which should you buy?
- LG confirms it will sell iPhones at South Korean stores