This is a list of characters in the anime and manga series Bleach who are hollows (虚（ホロウ）, horō?). Hollows are the central antagonists of the series. Series creator Tite Kubo uses many Spanish motifs in regards to hollows and their variants.

Hollows are departed human souls that have not been sent to Soul Society in due time, leading to their corruption. Once corrupted, they gain a skull-like mask, a drastically different physical appearance, and a very animalistic level of intelligence. Hollows crave other human souls, living or dead, to fill their empty hearts and ease their pain, starting with the persons it loved the most in its past life. They reside in Hueco Mundo when they're not scouring the human world for souls to consume. They will continue to search for and consume souls until they are slain by a Soul Reaper, at which point their souls are purified and they are allowed to pass on to Soul Society.

Some hollows have an unusually strong thirst for souls which leads them to consume other hollows. These hollows gather naturally, fighting to the death, and finally merging with one another, evolving into stronger and more intelligent forms known as menos (メノス, menosu?, Spanish for "minus" or "less"). Within the menos, there are three levels of evolution. The first of these is the gillian (最下大虚（ギリアン）, girian?, Japanese for "least of the great hollows"), large and powerful but possessing very low intelligence and no individuality, the result of the merging of hundreds of hollows. In the rare case a gillian retains its consciousness, it can continue to consume other gillians and eventually evolve into an adjuchas (中級大虚（アジューカス）, ajūkasu?, Japanese for "intermediate great hollow"), gaining a smaller body and superior strength, speed and intelligence, compared to their previous form. From there, some adjuchas have the potential to evolve into a vasto lorde (最上大虚（ヴァストローデ）, vasuto rōde?, Japanese for "Great king of the Hollows"). Vasto lorde are more humanoid in size and appearance and possess battle strength comparable or superior to a Soul Reaper captain, to the point where captain Tōshirō Hitsugaya speculates that Soul Society would be doomed if Sōsuke Aizen managed to get ten vasto lorde under his command.

As hollows evolve they gain access to unique skills and abilities, fueled by the souls they have consumed. The most basic of these abilities is Cero (虚閃（セロ）, Sero?, Japanese for "hollow flash," Spanish for "zero", labeled as "Doom Blast" in the Viz manga), high-powered energy blasts that can be fired from various body parts, such as the mouth or hand. There are at least two additional variants of the cero, though less commonly used.

Source: Wikipedia