Nestlé developed the pink treat in Japan year, derived from Ruby cocoa beans. The Kit Kat maker says this gives the chocolate an 'intense berry fruitiness' without the addition of any flavourings or colourings.
The firm says it is a new 'fourth type' of chocolate, after dark, milk and white.
A spokesman for the firm said: "Ruby chocolate has been attracting huge interest from chocolate connoisseurs throughout the world since its announcement in September last year and now Kit Kat fans in the UK will be able to get their hands on it.
"Kit Kat made with Ruby chocolate was first introduced earlier this year in Japan and Korea as Kit Kat Chocolatory Sublime Ruby sold exclusively at Chocolatory boutiques, complementing more than 350 Kit Kat‘ Made in Japan’ products in a huge variety of flavours."
The new four finger bar will only be available in Tesco in the UK when it launches.