The letter, published in the Sunday Herald today, also compares the break-up of the United Kingdom to the dissolution of the union between Sweden and Norway in the early 20th century, a move it says "benefited and enriched the political cultures of both countries".
Among the signatories to the letter are some of Scandinavia's most successful novelists and playwrights, including Jostein Gaarder, right, author of the multi-million selling novel Sophie's World, dramatist Jon Fosse, winner of the Ibsen Prize and widely tipped as a future Nobel laureate, and Anne B Ragde, whose 2009 novel Berlin Poplars has been translated into 15 different languages.
The letter was written by Thorvald Steen, president of the Norwegian Authors' Union between 1991 and 1997 and an honorary board member of writers' association PEN International. Speaking to the Sunday Herald, Steen said he felt compelled to intervene in the referendum debate because he believes a Yes vote this September would enhance Scotland's cultural life.
"Norwegian writers were very involved in winning Norway's independence in 1905.
"Independence was important to our language, our history and our identity - to our sense of ourselves as a people.
"For that reason, I think Scottish culture would absolutely benefit from independence. The London-based parties don't seem to understand how independence would strengthen the energy of the Scottish people, of Scottish writers and of Scotland's economy.
"A majority of Swedish politicians were against Norwegian independence. They said all these bad things would happen, but they didn't happen. And at that time Norway was much poorer than Scotland is now."
Another signatory, Norwegian author Tom Egeland - Scandinavia's answer to Dan Brown or Lee Child - said the letter was an expression of support for Scotland's "right to independence".
"In general, I support everyone who fights to be independent from a centralised power. If we look back at history, the Scots have over the centuries been systematically bullied by the centralised power in London, as have Ireland and Wales."
The letter adds to the growing number of non-Scottish artists and writers commenting on Scotland's constitutional future as the referendum approaches. Singer David Bowie and comedian Eddie Izzard have called on Scots to reject independence, while Icelandic rock group Sigur Ros and anti-war activist Tariq Ali have backed the Yes campaign.
According to Kari Dickson and Dr Arne Kruse from the department of Scandinavian Studies at Edinburgh University, there is a strong overlap between politics and culture in the Nordic countries, which may explain why so many high-profile writers were prepared to sign the letter. They said:
"[The letter] falls into a pattern where Norwegian and Swedish writers are actively engaged in international and local social debates. Generally, writers in Scandinavia carry a greater intellectual weight than they do here, [so] they are expected to have opinions.
"Jon Fosse and Jostein Gaarder are international literary figures, whereas many of the others are best-sellers within Scandinavia … Anne B Ragde is big in Germany, and Tom Egeland is very well-known too, particularly for his Bjørn Beltø series."
The Scottish Government's Cabinet Secretary for Culture and External Affairs Fiona Hyslop welcomed the letter, saying: "I'm delighted that these writers have thrown their weight behind an independent Scotland. Coming from prosperous and fair countries comparable in size to Scotland, these writers can clearly see the benefits of being in control of your own affairs.
She added: "It's certainly my experience talking to people overseas that Scotland's international brand is such that our creative industries will thrive as an independent nation."
Scottish Tory deputy leader Jackson Carlaw said: "The group certainly seem to be toeing the line very well, and sound as well-briefed as Nationalist MSPs on the subject of campaigning.
"But it is puzzling that the SNP object heavily to others within the UK making their voices known, but not seemingly Swedish and Norwegian intelligentsia."