Venus is closest at 0.796 astronomical units distance, Mars next at 2.022 astronomical units, and Saturn a distant 10.191 astronomical units. Because distances to other planets are, well, astronomical if measured in miles or kilometers, astronomers usually measure them inastronomical units: an astronomical unit is the average distance between the Earth and the Sun, 93 million miles or 150 million kilometers.

Info courtesy of Starry Night Education.

Source: spacewire.blogspot.com