The ivory was destroyed at the foot of the Eiffel Tower, Radio France Internationale reported.
Poaching of elephants to obtain ivory is responsible for the near-extinction of the animals in Africa. Only 500,000 of the animals remain, which is less than half the total in 1980.
The French environmental activist group Robin des Bois has been asking the government to destroy the 17 tons of ivory the organization estimates the government is holding to ensure it never makes it back to the market.
French officials said in October they would not destroy the ivory, but then decided to do so.
"I think it's a chain reaction," Robin des Bois' Miriam Potter told RFI.
Potter said America has recently destroyed ivory and asked other countries to follow suit.
"China is going to destroy a lot of their stockpile, certain Indian provinces. Once one country takes the lead, other countries will follow," she said.
The ivory destroyed Thursday had been seized at the Charles de Gaulle airport, and included 698 whole tusks and more than 15,000 small pieces of ivory, including jewelery and figurines.