Celery growing in East Anglia was only revived in 2000 by grower G's Fresh, who led the PGI status bid.
Its marketing director Anthony Gardiner said: "It's been difficult to convey to shoppers what makes it such a premium product. We hope that this will raise its profile and draw attention to what makes it so different."
Usually available from October to December, the paler, "earthed-up" celery is said to get its nutty, bittersweet taste and crisp, tender texture in part from the deep, peaty Fenland soil.
The designation, which follows a four-year application process, protects the vegetables from imitation throughout the EU.
Over 30 UK food products with sales totalling £1bn now have PGI status, which was introduced in 1993.