The Beast Ball (Japanese: ウルトラボール Ultra Ball) is a type of Poké Ball introduced in Generation VII. It can be used to catch a wild Pokémon, being more likely to succeed against Ultra Beasts and less likely against other Pokémon.

In Pokémon Sun and Moon, Beast Balls were developed by Faba of the Aether Foundation, building on the work of a predecessor. In Pokémon Ultra Sun and Ultra Moon, they were created through cooperation between the Aether Foundation and the Ultra Recon Squad.

When used from the Bag in a wild encounter, it attempts to catch the wild Pokémon. If the wild Pokémon is an Ultra Beast, it has a 5× catch rate modifier; otherwise, it has a 410/4096× (~0.1×) modifier.

Beast Balls cannot be used in situations in which Poké Balls cannot be used, such as in wild battles with two or more opponents currently present or against a trial Pokémon. If used in a Trainer battle, the opposing Trainer will bat the ball away, wasting the player's turn.

Fling fails if the user is holding a Beast Ball.

In Pokémon Sun and Moon, Lusamine is seen releasing a Nihilego from a Beast Ball in a cutscene before merging with it.

In Pokémon Ultra Sun and Ultra Moon, Ultra Recon Squad members keep their Pokémon in Beast Balls.

In Pokémon GO, the Beast Ball is a special, event-exclusive Poké Ball used during Ultra Beast encounters. They have a drastically improved catch rate when used against an Ultra Beast. Like the Premier Ball, it is never put into the player's Bag and cannot be kept after the encounter.

Currently, the Beast Ball is only available in Pokémon GO during in-game events. When these events are active, Beast Balls are the only kind of Poké Ball that can be used to capture an Ultra Beast.

Beast Balls debuted in A Mission of Ultra Urgency!, where the Aether Foundation provided many of them for Ash and his classmates to use during their Ultra Guardians missions. In the same episode, Ash used one of them to temporarily catch a Buzzwole.

In Love at First Twirl!, Ash used almost every Beast Ball provided to the group to try and catch a Poipole in order to take care of it until the location of its Ultra Wormhole could be discovered. He eventually succeeded with the last one in the box.

In Rise and Shine, Starship!, Ash and Kiawe tried to use Beast Balls to catch a Celesteela, but they both failed due to it being rooted down to the ground at the time.

In Twirling with a Bang!, Lana and Lillie used a pair of Beast Balls to temporarily catch a Xurkitree and a Blacephalon, respectively.

In The Long Vault Home!, Ash, Lana, Kiawe, and Mallow each tried to catch a Stakataka with multiple Beast Balls, but it effortlessly dodged them all. Eventually, Ash was able to successfully catch Stakataka after getting rid of the statue that had been placed on top of its body and convincing it that they were going to return it to its home.

In Beauty is Only Crystal Deep!, Ash used a Beast Ball to temporarily catch a Pheromosa so that it could be returned home.

In Living on the Cutting Edge!, Lana tried to use a Beast Ball to catch a Kartana, but it simply sliced the Ball to pieces.

In The Homecoming Crown!, Lillie's family used a Beast Ball to catch a Shiny Nihilego, nicknamed "Lillie", that had taken care of Mohn, with Gladion taking it under his care.

Beast Balls were created for Aether Foundation by Colress with help from the Ultra Recon Squad as a means of catching Ultra Beasts. They were first seen in Arrival at the Scientific Megalopolis, where Blake, disguised as Colress, delivered 100 of them to Lusamine in preparation for her plan to catch the ultimate Ultra Beast: Necrozma.

In Darkness!! The Mysterious Claws of Necrozma!, Lusamine used a Beast Ball to catch the Naganadel that Phyco had used to ride through Ultra Space. In Madness!! Mother Lusamine!, after riding the Naganadel to Ultra Megalopolis, she started throwing her Beast Balls at Necrozma. While her attention was focused on Necrozma, Sun used one of the Beast Balls that Lusamine had dropped to catch himself a Stakataka. Moon also tried to use a Beast Ball to separate Lusamine from the Nihilego she had fused with, but she missed her target.

In Transcend!! Ultra Necrozma!, Anabel was revealed to be in possession of the last known Beast Ball, which she was delivering to Mount Lanakila, where Sun and Zygarde were engaged in a battle with Necrozma. In Finale!! The Battle Against the Other Dimension!, Necrozma was defeated, but its last-ditch attack hit Looker and Anabel's balloon, destroying the Beast Ball. Sun then revealed that the Beast Ball that Moon had tried to use on Nihilego earlier had ended up at Mount Lanakila through an Ultra Wormhole. He offered it to Anabel, but she believed that humanity shouldn't be entrusted with Necrozma's power, and instead gave the Beast Ball to the Ultra Recon Squad, with Zossie using it to catch Necrozma.

The Beast Ball, released in the Celestial Storm expansion, allows the player to look at their Prize cards. If an Ultra Beast is found, they may reveal it and add it to their hand, replacing the Prize card with Beast Ball.