Hard Spell, which will be broadcast on BBC1 in November, will be based on Spellbound, the recent documentary which followed pupils during a US spelling bee.
Next month all UK secondaries will be sent vocabulary booklets and entry forms. Winners of regional heats will take part in a one-hour national final.
Karen Smith, Hard Spell executive producer, said: "Everyone takes spelling tests at school. But we want to make it glamorous. This will be like Pop Idol, but with spelling. We want it to be fashionable to spell well."
But Trevor Millum, of the National Association for the Teaching of English, said: "This is a bit of fun, but it shouldn't be confused with education for literacy. You can have technical perfection and still not have anything to say."
Words tested will range from the immediately intimidating, such as onomatopoeia, encyclopaedia and diarrhoea, to the deceptively simple separate, definite and indispensable.
But many English teachers have doubts about the benefits of memorising lists of Greek derivatives. Nicola Jeffs, deputy head of English at Beauchamp college, in Leicestershire, said: "Just because you can spell a word it doesn't necessarily follow you know what it means. This tests memory rather than ability. I don't think children will think spelling is cool, even if it is on TV."
Jean Comerford, at Alsop high, in Liverpool, said: "Bright kids will benefit, but the others will just end up feeling left out."
Ms Smith said the programme would be educational as there will be a definition with every word.