The Civil Defence Act 1948 (12, 13 & 14 Geo. 6. c. 5) was an act of the Parliament of the United Kingdom.
It sets out legislation for civil defence procedures in the United Kingdom.
Local authorities were required to plan for an attack by a hostile power. The act also allowed the relevant minister to designate functions for local authorities to perform under the act.
The act was amended by the Civil Defence (Grant) Act 2002 to allow for a mechanism which would determining grants to local emergency planning units.
It was repealed and replaced by the Civil Contingencies Act 2004.