Lloyd-Pack was born in Islington, London, the son of Ulrike Elizabeth (née Pulay, 1921-2000), an Austrian Jewish refugee who worked as a travel agent, and Charles Lloyd-Pack (1902-1983), who was also an actor. He attended Bedales School near Petersfield in Hampshire, where he achieved A Level passes in English, French and Latin. He subsequently trained at the Royal Academy of Dramatic Art (RADA), where he worked with actors including Kenneth Cranham and Richard Wilson.
Lloyd-Pack was married twice: first to Sheila Ball, from whom he was divorced in 1972, and secondly to the poet and dramatist Jehane Markham (the daughter of David Markham), whom he married in 2000. He had one daughter, Actress Emily Lloyd, and three sons. He lived most latterly in Kentish Town, North London, but also had a home near Fakenham in Norfolk.
In 2005, he appeared in the second series of ITV's Doc Martin as a farmer who held a grudge against Doctor Ellingham for what he believed was the malpractice-related death of his wife. In 2006, he played John Lumic and provided the voice of the Cyber-Controller in two episodes of Doctor Who, "Rise of the Cybermen" and "The Age of Steel", opposite David Tennant, who had played his son in the same Harry Potter film. Lloyd-Pack's final TV appearance was in Law & Order: UK as Alex Greene.
In a 2008 interview, when asked what profession he would have chosen aside from acting, Lloyd-Pack said: "Psychiatrist or a psychoanalyst or something in the psycho world because I’ve always been interested in that... or I might have been a Photographer... I also would have loved to have been a musician." In that same interview, he listed his favourite Directors as Peter Gill, Harold Pinter, Richard Eyre, Thea Sharrock, and Tina Packer, and also listed actor Paul Scofield as both a favourite and influence.
In January 2012, he and fellow actor Sarah Parish supported a campaign to raise £1million for The Bridge School in Islington.
On 15 January 2014, Lloyd-Pack died of pancreatic cancer at his home in Kentish Town at the age of 69. His funeral was held at the church of St. Paul's, Covent Garden. He was buried in Highgate Cemetery, North West London.
