The second closest known galaxy is usually taken to be the Sagittarius Dwarf Elliptical Galaxy, at about 70,000 light-years from the Sun. Another nearby candidate often listed right around that spot is the Canis Major Dwarf Galaxy, at about 25,000 light-years from the Sun, depending on how “closest” is being counted.

Why it can vary

Astronomy lists can differ because some include:

  • Satellites of the Milky Way.
  • Only “major” galaxies.
  • The distance from the Sun versus the distance from the Milky Way’s center.

So the answer changes a bit depending on the rule being used.

Simple version

If you mean all known nearby galaxies , then the second closest is commonly given as the Sagittarius Dwarf Elliptical Galaxy , about 70,000 light-years away.