NO! The United States is a Republic. Its citizens elect representatives (the Congress). The founding fathers warned of the problems of democracy and the tyranny of the majority in many early writings. Think of the Pledge of Allegiance, "... and to REPUBLIC for which it stands..."
You will find no mention of democracy in the US Constitution.
Actually we are a representative Democracy... and a Republic. What we aren’t is a direct Democracy. Being a representative democracy does not in any way make us not a Republic.