I made a diagram with the distances on it. These are only average distances because the planets orbit the sun in an elliptical orbit, so they are farther and closer to it. But to answer your question, Mercury is closest to the sun, just 58 million kilometers away. :) [img alt_text = 'planets of the solar system' description = ''] https:///wp-content/uploads/2017/01/bojgok.jpg [/ img]