The Criminal Law Act 1967 (c. 58) is an act of the Parliament of the United Kingdom that made some major changes to English criminal law, as part of wider liberal reforms by the Labour government elected in 1966.

This Part implements the recommendations made by the Criminal Law Revision Committee in their seventh report.

Originally, all crimes in English law were categorised in a hierarchy of treason, felony, and misdemeanour, each with its own rules of procedure and evidence.

The section set out the circumstances in which a citizen or a constable could arrest somebody without a court warrant (police powers were more extensive than a civilian's).

Sections 24 and 25 were controversially amended by the Serious Organised Crime and Police Act 2005, which abolished the difference between arrestable and non-arrestable offences and substituted one set of police arrest powers for all offences, irrespective of the maximum sentence.

(Further provision about when force is "reasonable" was made by section 76 of the Criminal Justice and Immigration Act 2008.)

The definition of what constitutes a 'crime' was clarified under R v Jones (Margaret), R v Milling et al [2006] UKHL 16, which stated it covered any domestic criminal offence under the law of England and Wales.

It stated that a person who has information which might lead to the prosecution of an arrestable offence and who agrees to accept consideration (other than [victim] compensation for the offence) in exchange for not disclosing that information to the authorities is liable to two years' imprisonment.

This means that: Consequential repeals on s.5(5) (s.10(2) and Sch 3, Pt III) Section 6 deals with the procedures for arraignment and verdict.

It also repealed the offence of praemunire (attempting to appeal to a foreign power, e.g. the pope, on legal matters), which had survived on the statute books since 1392.