Misuse of Drugs Act is the name of several similar national drug control laws passed by countries in the Commonwealth of Nations

Commonwealth of Nations

The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 and by the Republic of Ireland

Republic of Ireland

Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

. With the exception of Ireland's 1977 Act, they all sort drugs into three categories, Classes A, B, and C. This classification system was influenced by the Single Convention on Narcotic Drugs

Single Convention on Narcotic Drugs

The Single Convention on Narcotic Drugs of 1961 is an international treaty to prohibit production and supply of specific drugs and of drugs with similar effects except under licence for specific purposes, such as medical treatment and research...

 and other drug control treaties.

Some of the Acts are:

• Misuse of Drugs Act (Australia);
• Misuse of Drugs Act (Belize)
  Misuse of Drugs Act (Belize)
  The Misuse of Drugs Act is a national drug control law of Belize that divides drugs into three classes. There does not seem to be any mechanism for adding, removing, or transferring drugs between classes without amending the statute...
  
  
• Misuse of Drugs Act (Ireland)
  Misuse of Drugs Act (Ireland)
  The Misuse of Drugs Act 1977, the Misuse of Drugs Act 1984, and the Criminal Justice Act 2010 are the acts of the Oireachtas regulating drugs in Ireland...
  
  
• Misuse of Drugs Act 1975 in New Zealand
• Misuse of Drugs Act (Singapore)
  Misuse of Drugs Act (Singapore)
  The Misuse of Drugs Act is a national drug control law classifying substances into three categories, Classes A, B, and C. Section 44 provides that "The Minister may, by an order published in the Gazette" add, remove, or transfer drugs among the classes...
  
  
• Misuse of Drugs Act 1971
  Misuse of Drugs Act 1971
  The Misuse of Drugs Act 1971 is an Act of Parliament which represents UK action in line with treaty commitments under the Single Convention on Narcotic Drugs, the Convention on Psychotropic Substances, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic...
  
  in the United Kingdom