I would imagine that it would be in the US, where the descendants of Scandinavians settled in the 19th and 20th centuries: Wikkipedia estimates that there are 5 million descendants of Norwegians, mostly living in the Upper Midwest. Danish Americans: Danish Americans are Americans of Danish descent. There are about 2 million Americans of Danish descent. Like other groups of Americans of Scandinavian descent, many of them are Lutherans. However, they contrast with Norwegian and Swedish Americans in that a large fraction were Mormon converts who settled in Utah and southeastern Idaho. Nebraska, Iowa and Wisconsin have the largest concentrations of non-Mormon Danish Americans. Solvang, California, is an example of a community formed by Danish Americans. Racine, Wisconsin, claims to be the home to the largest group of Danish Americans in the United States. Swedish Americans:Most likely, about 8 million Americans have Swedish roots, of whom 4.5 million have been confirmed as Swedish Americans. Most Swedish Americans are Lutherans affiliated with the Evangelical Lutheran Church in America or Methodists. Finnish Americans are Americans of Finnish descent, who currently number at about 700,000. There are 43 000 Icelandic Americans That makes over 15 000 000 Scandinavian Americans. The present population of Scandinavia is about 25 million BUT it must be remembered that the Vikings also established colonies and kingdoms in large parts of the UK (called the Danelaw in pre-Norman England), and left much DNA there. I myself have plenty of Viking blood) and northern France (the Normans, who invaded English were Danish in origin: Rollo the Viking founded the Norman state in the late 900s) and we cannot also forget, even more importantly that the Russians have much Viking blood. The Vikings founded settlements down the Volga, including Kiev, and got as far as Constantinople in their trading. So huge numbers of Russians and Ukrainians would also possess Viking blood. This would bump up the numbers of US citizens with Viking blood to much larger than the population of Scandinavia, perhaps rivalling that of the Ukraine/Russian Viking descendants.