A galaxy filament is a type of naturally-occuring cosmological structure composed of thousands to millions of gravitationally bound galaxies stretched out into a strand over dozens to hundreds of megaparsecs. Between them are voids, and they become thinner and less well-defined as a universe expands and these voids get larger. Just about any imaginable types of galaxy can be found in a filament, and in large numbers.
Particularly large filaments or groups of filaments can be referred to as Galaxy walls.
| Galactic Filament Classes |
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| Galaxy filament · Galaxy wall · Supercluster complex · Great wall |