Yes, gravity exists in other galaxies just as it does in our own. Here's why:

* Gravity is a fundamental force of nature. It's not limited to our galaxy, the Milky Way. It acts on all objects with mass, everywhere in the universe.

* Galaxies are held together by gravity. The massive stars, gas, and dust that make up galaxies are bound together by their mutual gravitational attraction.

* Dark Matter: Galaxies also contain a significant amount of dark matter, which we can't see directly but we know exists due to its gravitational effects.

So, in short, every galaxy is a collection of objects held together by gravity.