The site, discovered near Cumwhitton in northwestern England, is believed to date to the early 10th century, and archaeologists working there called it one of the few Viking burial grounds ever found in Britain.
The only other known Viking cemetery in England was found in Ingleby, east of Cumwhitton. It was excavated in the 1940s, but the bodies had been cremated and not buried.
A Viking war grave uncovered near Repton in central England contains the remains of 249 individuals, but is an ad-hoc battlefield site rather than a formal cemetery.
Local metal specialist Peter Adams made the Cumwhitton find at the end of March and reported it to the Portable Antiquities Scheme, which is run by the Museums, Libraries and Archive Council.
"This is tremendous news, a unique discovery which will improve people's understanding of the area and its history," council chairman Mark Wood said on Monday.
The Vikings, inhabitants of Scandinavia from 800 to 1100, traded with, and raided, much of Europe, often settling there. They invaded and conquered England in 1013.
The burial ground was unearthed when Adams found two copper brooches. The grave of a Viking woman was found underneath, and further excavation led to the discovery of the graves of another woman and four men.
Among the items found in the graves were weapons, spurs, a bridle and a drinking horn, as well as a jet bracelet and a copper alloy belt fitting.
Adams described it as "the find of a lifetime."
Rachel Newman, of Oxford Archaeology North, said: "We could not have expected more from the excavation of the site.
"We knew the brooches found by Mr. Adams came from a burial of a Viking Age woman, which was exciting and of great importance in itself. But we did not expect to find five other graves complete with such a splendid array of artifacts. It truly has been an amazing few months excavating this extremely important Viking Age site."
Arts Minister Estelle Morris said: "We should all be grateful to Mr. Adams, who recorded his find so promptly. As a result, the experts have been able to learn more about this fascinating site and uncover the secrets of a time capsule more than 1,000 years old."
Some of the items found were to be shown Tuesday at the Tullie House Museum and Art Gallery in the nearby city of Carlisle.
Vikings also were among the earliest explorers of North America. Leif Ericcson is believed to have made landfall somewhere on the eastern coast of the continent around the year 1002.