Desmond James Conrad Ackner, Baron Ackner, PC (18 September 1920 – 21 March 2006) was a British judge and Lord of Appeal in Ordinary.
Ackner was the son of a Jewish dentist, Dr Conrad Ackner, from Vienna, who came to Britain before the First World War. He was educated at Highgate School, before attending university at Clare College, Cambridge, where he read economics and law, and where he was later an honorary Fellow. During the Second World War, he was commissioned into the Royal Artillery, although a twisted foot kept him out of active service and he was transferred to the Admiralty's naval law branch.
Ackner was called to the bar by the Middle Temple in 1945, practising mainly commercial law. He became a Queen's Counsel in 1961, a Bencher of Middle Temple in 1965 and was later Treasurer in 1984. He came to public notice acting for victims of thalidomide in the late 1960s in their action for damages against the manufacturer of the drug, Distillers, which was settled before trial, and as counsel for the families of the victims at the public inquiry into the Aberfan disaster in 1967, in which he condemned the "callous indifference, incompetence, ignorance and inertia" in the National Coal Board. Ackner proved to be an inspired choice and he remains a local hero in Aberfan, where a bench in the memorial garden bears a plaque in his memory.