Some 557 people have claimed Cornish is their main language in the 2011 Census.
In Cornwall alone, 464 people stated Cornish is their mother tongue, according to the Office for National Statistics, or 0.1% of the local population.
Encouragingly for campaigners championing Cornish heritage, the language appears to be spreading beyond the Duchy.
Neighbouring Devon boasts 12 Cornish speakers and 13 residents in the north London borough of Haringey purport to favour Cornish. Manchester, Lincoln and Solihul near Birmingham boast a Cornish speaker apiece.
But the figures may raise eyebrows. The Cornish Language Board believes only 300 people are "fluent" in the language.
Census figures are prone to manipulation, as witnessed by the thousands claiming to be Jedi Knights – a fictional quasi-religious order featured in the Star Wars films.
Along with Welsh and Breton, Cornish is a Brythonic tongue descended from the ancient British language spoken throughout much of Britain before English came to dominate.
It was the main language of Cornwall for centuries, continuing to be dominant in some parts until the late 18th century. Henry Jenner led a revival in the early-20th century, with interest growing significantly since the 1980s.
North Cornwall MP Dan Rogerson said: "We know that there are thousands of people learning the language – and as far away as the US and Australia."
Western Morning News Living Cornwall Editor Simon Parker said: "Cornish is far more widely used than it was even ten years ago. Most people in Cornwall now have a smattering of words in their vocabularies. Whatever the motivation of the 464 people claiming Cornish as their 'main language' it has to be good for Cornish culture and heritage."
But Polish appears to be Cornwall's second language, with 1,984 people (0.4%) saying it is their main language. Even 16 people on the Scilly islands (0.7%) speak Polish first.