When was the supply and demand model first used? Who created the supply and demand model in economics or when was it first used?
The Wikipedia page about the supply and demand model has a History section. 

According to Hamid S. Hosseini, the power of supply and demand was understood to some extent by several early Muslim scholars, such as fourteenth-century Syrian scholar Ibn Taymiyyah, who wrote: 


  "If desire for goods increases while its availability decreases, its
  price rises. On the other hand, if availability of the good increases
  and the desire for it decreases, the price comes down."


Antoine Augustin Cournot first developed a mathematical model of supply and demand in his 1838 Researches into the Mathematical Principles of Wealth, including diagrams. However, John Locke (1691), Adam Smith (1776) and David Ricardo (1817) also used this model.