Waitrose will stock the Chichester glasshouse-grown Diamond Jubilee berries from 26 March, claiming it is the first time consumers have been able to enjoy locally grown varieties in March.
The berries are grown in glasshouses by Harry Hall, who supplied the supermarket with the first strawberries of the season earlier this month.
Laurence Olins, chairman of industry body British Summer Fruits, said the berries were the result of a trial plot of the "very sweet" Diamond Jubilee berries planted by Mr Hall.
Just 200kg of the berries are expected this week, but there should be around a tonne produced every week afterwards.
Mr Olins said: "This is probably the earliest we've seen English raspberries."
The early delivery follows British-grown strawberries becoming available weeks earlier than previous years.
This is thanks to the weather this winter, which the Met Office has said was the sunniest since records began in 1929.
The figures for rainfall and temperature were average, but the number of sunny days was 125% of the long-term average.
Waitrose's raspberry buyer Nicki Baggott said: "This is the first time we've been able to offer British-grown raspberries so early in the year.
"It's incredibly unusual to have these ready in March, but a combination of growing techniques and the perfect weather have meant we can sell these juicy delights earlier than ever."
Raspberries were once regarded as a late summer crop, but British Summer Fruits said growers are using new varieties and innovative methods to extend the season.