That figure is made up of 916,000 people living in Switzerland and around 560,000 Swiss citizens living overseas.
It means close to one in four Swiss citizens now holds a second passport. The most common nationalities involved are Italian, French, German and Turkish.
Read also: How to apply for Swiss citizenship in 2018
These figures were published by Swiss newspaper NZZ in the wake of comments from Swiss People's Party (SVP) figurehead Christophe Blocher about controversial goal celebrations by Swiss football players at the World Cup.
During a recent match against Serbia, Switzerland's Xherdan Shaqiri and Granit Xhaka, both of whom have a Kosovo Albanian background, celebrated their goals by making a hand gesture representing the “double eagle” of the Albanian flag.
The celebrations reignited an ongoing debate in Switzerland about what it means to be Swiss at the start of the 21st century.
When Blocher was asked what he thought of the goal celebrations, he said: “Just having the citizenship doesn't mean you are Swiss.”
Dual nationality for Swiss citizens became legal in 1992. Growth in the number of its citizens with two passports has been fuelled by migration and more marriages between people of two different nationalities. The children of these marriages can then have the right to two passports.
The SVP has periodically called for the right to dual nationality for Swiss people to be either limited or scrapped, arguing that the holding of two passports can mean reduced loyalty to Switzerland.
Swiss people with dual citizenship are currently not excluded from sensitive positions within the police force or from border security roles. They can even work as diplomats for Switzerland.
Dual nationals can also take an active role in politics. Current foreign affairs minister and member of the Swiss government Ignazio Cassis also held an Italian passport before he took office. He gave this up when he was sworn in although he was not obliged to do so.
There are also dual nationals in the parliament although the exact number is not known as politicians are not required to declare their second passport. This lack of requirement to declare a second nationality is something SVP MP Marco Chiesa would like to see changed.
Meanwhile, there is also criticism from within the SVP that some dual nationals make opportunistic use of their status to avoid obligations such as Swiss military service.
Swiss nationals with French or Austrian passports can choose to do their military service in those countries. In 2017, 669 French–Swiss nationals chose to do that service in France. In Switzerland, compulsory military service has a duration of 245 to 280 days. In France, military service has been phased out.