Yes, pure, distilled vodka, even if made with wheat, barley, or rye, is considered gluten-free.
Most vodkas are safe for people with celiac disease because of the distillation process. However, be on the lookout for hidden gluten in vodkas that may add flavourings or other ingredients after distillation. Vodka is typically just water and ethyl alcohol but sometimes can contain traces of other ingredients. Sourced from @beyondceliac
Brands that advertise they are Gluten free, are just stating they do what most distilleries do.
We do not add anything after distillation to our products that contain any sort of Gluten.
Now you know.