The Essential Commodities Reserves Act, which allowed the British government to build up reserves of essential commodities in anticipation of war, received royal assent.

The Essential Commodities Reserves Act 1938 is an Act of the Parliament of the United Kingdom. It was passed in anticipation of the Second World War and allowed the Board of Trade to build up stockpiles of commodities considered to be essential, specifically foodstuffs, animal feed, fertiliser and petroleum products as well as the raw resources needed to manufacture these products. They paid traders at least £13.5 million to stockpile materials in the following year and a half. The act was largely superseded by the Emergency Powers (Defence) Act 1939 and the establishment, in the same year, of the Ministry of Supply. The stockpiles and associated funding were wound up by 1947 and the act has not been made use of since. It was proposed for repeal by the Law Commission in 2015.