The Regency Act 1830 (1 Will.4 c.2) was an Act of the Parliament of the United Kingdom passed to cater for the event that King William IV died while the next person in line to the throne was not yet aged 18. It provided for a regency until the new monarch reached the age of 18, and also would have enabled a posthumous child of King William IV to replace Queen Victoria on the throne. However, the Act never came into force, because William was not survived by a legitimate child and Victoria became queen at the age of 18 in 1837.