Who created the Hunger Games?

President Snow and his men in the Capitol would have created the concept of it.

The Games were Created through a Treaty of Treason with which came New Laws to Create Lasting Peace. One of those new Laws were the Creation Of the Hunger Games. So it wasn't created realy by a who but a what but for the who at the time would be the Government of Panem (Not President Snow, He came to power at around the 10 - 15th Games {as Discovered in Mockingjay}). The Games are used to keep a pecking order between the districts and the Capitol aswell as to show that the Capitol is in charge and the districts are the slaves.