[1][2] Grillo was educated at Watford Grammar School for Boys and Trinity Hall, Cambridge, and while there was actively involved in student theatre.
[3][4] He played Mr. Samgrass in the ITV series Brideshead Revisited, and Phillip Marriott QC in Crown Court.
[5][6] He had minor parts in other shows, including Blackadder II ("Bells"), Bergerac, Capital City, EastEnders, Blott on the Landscape, Maisie Raine, Mike and Angelo, Bramwell, The Bill, Prince Regent, Cracker, The Darling Buds of May, Foyle's War, The Grand, Taggart, The Broker's Man, Oliver Twist, Mother Love and Rumpole of the Bailey.
[8] In 1997 he appeared as Mr Carkdale, the English teacher who spoke only in Anglo-Saxon, in two series of Steven Moffat's school-sitcom Chalk.
[9] His film credits include appearances in Scum, A Murder of Quality, Firefox, Brazil, Blame It on the Bellboy, Danny the Champion of the World, Christopher Columbus: The Discovery, Orlando, Jack and Sarah, FairyTale: A True Story, Jinnah, The Affair of the Necklace, and Max.