Diamond Head, cited as an influence by top acts such as Metallica and Megadeth, will perform at the festival near Lichfield on the event's final day - Sunday, August 9.
Considered one of the leaders of of the New Wave of British Heavy Metal movement, Diamond Head formed in 1976 and released their latest album The Coffin Train in May. They will play the main Ronnie James Dio stage.
Heavy metal icon Philip H Anselmo, meanwhile, will perform at the open air event on Friday, August 7 - also on the main stage.
The New Orleans-born singer, aged 51, will be joined by his band The Illegals, though festival organisers have promised their set will comprise 'a slew of Pantera classics'.
Saturday, August 6, will see gothic metal act Paradise Lost perform their fifth album Draconian Times in full. The record, released in 1995, featured tracks such as The Last Time and Forever Failure.
Playing the main stage the following day will be alternative metallers Life of Agony from New York.
The band's new album The Sound of Scars - released just 11 days ago - serves as a sequel to their debut release River Runs Red.
These acts will be joined by the previously announced line-up of Devin Townsend, Skindred, Black Dahlia Murder, Jinjer, Vio-lence, Sacred Reich, Gloryhammer, Dark Tranquillity, and Butcher Babies.
Bloodstock Open Air Festival takes place at Catton Park, Derbyshire, from August 6 to 9, 2020.
Next year's festival will mark 20 years of the heavy metal event.
Campervan tickets for the event have already sold out.
To book tickets, visit https://www.bloodstock.uk.com/