Is the Arc de Triomphe a UNESCO World Heritage Site?

No. The Arc de Triomphe (Paris, 1836) is a national monument but not inscribed on the UNESCO World Heritage List. Paris's UNESCO sites include: Banks of the Seine (Notre-Dame, Louvre, Eiffel Tower vicinity), Palace of Versailles, and Palace of Fontainebleau. The Arc is part of the "Banks of the Seine" buffer zone but not a listed property itself.