What is the earth's biggest satellite?

Answer 1

If you are referring to artificial satellites (which I think you are) it has to be the ISS (International Space Station)
Only one natural satellite of the Earth is known ... the one known as "The Moon".

Being the only one, it's also the largest.

It's also far larger than any of the artificial satellites, so it's the largest satellite of Earth, period.

The largest artificial satellite of Earth currently is the International Space Station, which I believe is also the largest artificial satellite of Earth ever.

Answer 2

The Moon, also called Luna. That big shiny thing in the sky at night.

Answer 3

The Earth's biggest satellite is the Moon. It is about 1/6th the size of Earth and is the only natural satellite of our planet.