This page lists the official or unofficial symbols for the largest named objects in the Solar System, ranked by mass. It only includes those objects that have a mass of at least 1019 kg (10 Zg) and that have been given permanent names. For the planets and sun I show their traditional symbols. The moons of other planets and large trans-Neptunian objects are accompanied by the symbols I've created for them. The asteroid symbols are from diverse sources - see that page for details. Uranus, Pluto, Pallas, and Vesta have multiple widely accepted symbols - in each case, I've chosen one based on my own aesthetic preferences. Mass data is from Wikipedia.
I also have a version of this page with the names and sizes of the objects.