As Lord Chief Justice

Lord Goddard announced his resignation as Lord Chief Justice in 1958. He had been an exception to the tradition that the Attorney General be appointed to the role and some commentators expected that the next appointment would therefore be Sir Reginald Manningham-Buller, Attorney-General at the time. However Manningham-Buller was widely disliked and also shared Goddard's reactionary views on criminal justice. Harold Macmillan considered Viscount Kilmuir, the Lord Chancellor, but Kilmuir rejected the job. Macmillan therefore decided to appoint a senior judge, and Parker's name emerged as the one candidate with whom most people were happy.^[1] On 30 September 1958, Parker took the title Baron Parker of Waddington, of Lincoln's Inn in the Borough of Holborn.^[3][2]

Parker's style was totally different from Goddard as he confined himself to the higher courts and did not intervene in everyday criminal trials. He had little interest in the social life of the judiciary. He was called upon where a trial had a serious political aspect, and was criticised when he imprisoned journalists who refused to reveal their sources during the Vassall tribunal of 1963. Parker's judgment stated in part "the citizen's highest duty is to the State". Parker also made history when he sentenced George Blake, convicted of spying, to 42 years imprisonment, the longest sentence then passed in an English court; the conjunction seemed to some to suggest that Parker was too close to the government of the day, though others said Parker had been shocked at the extent of the treachery that had sent dozens of Western agents to their deaths.^[2] Parker had himself said that the Courts "have a positive responsibility to be the handmaiden of administration rather than its governor".^[4]

However, Parker was popular among the profession as he secured improvements in judicial salaries and pensions. Parker was a mild reformer who supported legal aid and tried to modernise some judicial procedures which he thought were antiquated, such as the assize court system. Like Goddard, Parker took an active part in House of Lords debates. The most important speech he made was in debates during the passage of the War Damage Act 1965 which has the effect of retrospectively overturning the judicial decision of the House of Lords in Burmah Oil Co. v Lord Advocate thereby depriving the plaintiff of an award of damages. Parker regarded this as an abhorrent idea in principle, but his view did not carry the day. He supported moves to abolish the death penalty.^[1]

In 1964 Parker instituted the first 'Sentencing conference' to try to get consistency. In the late 1960s he introduced the first formal training for Judges, and welcomed the formation of the Law Commission. When Lord Beeching headed a committee looking at court reform in 1971, Parker's memorandum was more radical than the committee's recommendations.^[1]