For most Americans, the first question about a second passport is whether Uncle Sam will mind. The State Department confirms that Americans may hold dual or multiple citizenships, as long as they use a US passport to enter the United States.[1] The harder part is the other country, since its laws decide whether you can keep both nationalities.
Plenty of nations are fine with it, though the rules and timelines have shifted a lot in the past two years. Some countries have opened new doors, and others have narrowed old ones. The seven below are among the most practical options for Americans in 2026.
1. Canada
Canada permits dual and multiple citizenship, so you don’t have to renounce US or any other nationality.[2] The ancestry route changed in a big way recently. Bill C-3 came into force on December 15, 2025, and ended the limit that restricted citizenship by descent to the first generation born abroad.[3]
If you were born before that date and can prove an unbroken line to a Canadian ancestor, you might already be a Canadian citizen and only need to apply for proof.[4] Without Canadian roots, a Canadian passport can be obtained through naturalization after five years of residency.[5] Keep in mind that US tax duties don’t vanish. If you move to Canada, you file both US and Canadian returns.[6]
2. Italy
Italy is a common pick for Americans, and it’s on most lists of countries that accept dual nationals with the US. The descent route is much tighter than it used to be, though. Under the 2025 law change, you qualify by descent only if you have a parent or grandparent born in Italy who held only Italian citizenship at the time.[7]
The change has been tested in court. The Italian Constitutional Court upheld the restrictions of Law 74/2025 on March 12, 2026.[7] Applications submitted or formally scheduled before March 27, 2025 are evaluated under the old, wider ancestry rules.[7] For those who don’t qualify, citizenship by legal residence is still possible after living in Italy for at least two years under certain conditions.[7]
3. Ireland
Ireland shows up on major lists of countries that allow dual citizenship with the US, including the full dual citizenship category in one 2026 legal guide.[8] One other list treats Ireland as conditional, so it’s worth confirming the current rules with the Irish government before you apply. That kind of disagreement between guides is common, and official sources settle it.
The best known path for Americans is through ancestry. A person with a grandparent born on the island of Ireland can generally register through the Foreign Births Register. An Irish passport also carries European Union rights, which is a big part of the appeal.
4. United Kingdom
The UK has long accepted multiple nationalities. The UK allows its citizens to hold dual citizenship, and British citizens who acquire US citizenship don’t need to renounce their British nationality.[9] UK nationals, including those from British Overseas Territories, can generally hold dual citizenship as well.[1]
For Americans, the usual route is a British parent, or naturalization after years of lawful residence and settled status. Settlement rules have been under review in recent years, so check the Home Office guidance for current timelines. Don’t rely on older articles for the residence periods.
5. Germany
Germany used to be one of the toughest countries on this question. Germany has generally accepted multiple nationalities since June 2024, which means Americans who naturalize in Germany can now hold both citizenships.[1] That makes it a far more realistic option than it was a few years ago.
Some guides haven’t caught up. One still describes Germany as allowing dual citizenship only in limited cases, such as a child who gets both German and US citizenship at birth.[9] Pay attention to publication dates when you research. The 2024 reform is the reason older advice can look so different.
6. Portugal
Portugal accepts dual citizenship with the US, but it is now a slower route. Portugal’s nationality law, in force since May 19, 2026, raised the citizenship residency requirement to ten years, or seven for CPLP and EU nationals.[10] Americans, Brits and Canadians fall under the longer ten year period.[11]
The clock now runs from the date your first residence permit was issued, not from when you file.[10] There is a transition rule, too. If you filed with the IRN on or before May 18, 2026, the previous five year timeline still applies to your case.[12] Permanent residency is unchanged and can still be requested after five years of legal residence.[12]
7. Mexico
Mexico is a popular choice for Americans with family ties or plans to retire there. Mexico sits among the popular countries that allow dual citizenship with the US.[1] One 2026 legal guide also lists it among countries with full dual citizenship.[8]
A common route is through a Mexican parent. A person born in the US to a Mexican parent is generally a Mexican national by birth, and that status isn’t lost by holding another citizenship. Americans without Mexican parents can pursue naturalization after a period of legal residence, and the exact requirements depend on your circumstances.
