Where we always second guess!
In our solar system, Venus is the second-closet planet to the the sun. It orbits at an average distance of 67,238,251 mi (108,209,475 km) at a mean orbital velocity of 78,339mph (126,074 km/h).
The closest planet to the sun is Mercury. Its average distance from the sun is about 36 million mi (58 million km).