The Longarm Tribe is a tribe composed of people with long arms, which have two joints in them.
As their name suggests, all members of the Longarm Tribe seen so far have two elbow joints on each arm, which results in them having abnormally long arms. Furthermore, most members seen so far wear Chinese-style clothing, with a kanji in the front. The kanji varies from person to person. Other than that, they have the same appearance as normal humans. Ideo, in particular, kept his extra joint tucked above his shoulder which gives him the appearance of unusually long shoulders, and also allowing him to extend his arms at unexpected time and launch powerful punches.
|??????||??????||??????||????? *||Shuzo ≠|
|Ant De Bonham ≠|
|Charlotte Mobile||Charlotte Marble||Charlotte Myukuru||Charlotte Maple|
- †: the character is deceased.
- *: the character's status is unknown. Hovering the symbol may give further details.
- ≠: the character is non-canon.
- ‡: the character is no longer part of this group. Hovering the symbol may give further details.
Longarms and longlegs appear to maintain hostile relations, spanning a conflict that's been going for over a thousand years. However, not all long arms and longlegs are antagonistic with each other, with examples of interracial cooperation existing such as the Longlimb Humans and Ideo Pirates, which includes both Ideo and Blue Gilly.
Aside from the extra joint in their arms, they otherwise appear like normal humans. They are also known for being able to produce hybrid beings with members of the Longleg Tribe called Longlimb Humans. 
From two prominent members seen—Scratchmen Apoo and Ideo—the tribe's combat style revolves around their long arms and extra joint. Apoo uses his extra joint with his Devil Fruit power to transform them into weaponized musical instruments, while Ideo compresses his joint up to his shoulder to create explosive punching power and act as a surprise attack.
Apparently they are the ones responsible for destroying the country Harahettania on Namakura Island. The cultists of Namakura Island were in the middle of trying to summon Satan, wanting him to help them destroy the Longarm Tribe. However, due to Bartholomew Kuma, Brook landed right in the middle of the summoning. Believing him to be Satan, the people of Namakura Island wanted him to help them get revenge on the Longarm Tribe. Sancrin and two other members of the Longarm tribe kidnapped Brook to put him on display as the world's only moving skeleton.
Two years later, the three longarms who kidnapped Brook all became his managers when he became a famous rockstar known as "Soul King". However, upon learning that Brook was a pirate, and that he planned to retire after one final concert in order to rejoin the Straw Hats, the three called the Marines to turn him in, but the fans prevented the Marines from arresting Brook so that he could perform his last song. His managers were furious when Brook escaped with the help of the Rosy Life Riders.
- They appear to be based on Japanese legendary creature called a Tenaga-jin (手長人?), whose most notable characteristic is their long arms. They are half of a pair called Ashinaga-tenaga (足長手長? "Long Legs Long Arms"), the other being the Ashinaga-jin (足長人?), which the Longleg Tribe is based on.
- Unlike their counterpart, the Longleg Tribe, the Longarm tribe has two joints in their characteristic long limbs.