Official Secrets Act 1939

The Official Secrets Act 1939[1] (2 & 3 Geo. 6. c. 121) was an Act of the Parliament of the United Kingdom. It substituted a new section 6 into the Official Secrets Act 1920, which limited the scope of that offence to offences under section 1 of the Official Secrets Act 1911 (it had formerly applied to all offences under the Official Secrets Act 1911 and to all offences under that Act).

Official Secrets Act 1939[1]
Act of Parliament
Long titleAn Act to amend section six of the Official Secrets Act 1920.
Citation2 & 3 Geo. 6. c. 121
Royal assent23 November 1939
Commencement23 November 1939[a]
Repealed20 December 2023
Other legislation
AmendsOfficial Secrets Act 1920
Repealed byNational Security Act 2023
Relates toOfficial Secrets Act 1911
Status: Repealed
Text of statute as originally enacted
Text of the Official Secrets Act 1939 as in force today (including any amendments) within the United Kingdom, from

It was enacted in reaction to the "Sandys affair" in 1938, when Duncan Sandys MP was threatened with prosecution under section 6 in an attempt to get him to disclose who had given him information about the inadequate state of the air defences around London.

The Act was repealed by and replaced with the National Security Act 2023.[2][3][4]

See also



  1. ^ This Act came into force on the date on which it received royal assent because no other date was provided: Acts of Parliament (Commencement) Act 1793


  1. ^ a b This short title was given to this Act by section 2(1) of this Act.
  2. ^ "National Security Act Factsheet - Home Office in the media". Retrieved 24 October 2023.
  3. ^ "National Security Act 2023: Schedule 18",, The National Archives, 11 July 2023, 2023 c. 32 (sch. 18), retrieved 20 December 2023
  4. ^ "The National Security Act 2023 (Commencement No. 1 and Saving Provision) Regulations 2023",, The National Archives, 27 November 2023, SI 2023/1272, retrieved 20 December 2023