Mobile Legends: Bang Bang (MLBB), commonly referred to simply as Mobile Legends (ML), is a multiplayer online battle arena (MOBA) game developed and published by Moonton, a subsidiary of ByteDance. Since its release in 2016, MLBB has been free-to-play and is monetized through purchasable character and cosmetic customization. The game is primarily played on smartphones and tablets and is available for iOS and Android.

In its core modes, Classic and Ranked, the game places two teams of five players against each other in real time, with matchmaking usually taking 20 to 60 seconds and matches lasting between 10 and 30 minutes on average. Following the classic MOBA format, players compete across three lanes, aiming to destroy the opposing base while defending their own and securing objectives to gain an advantage. Outcomes are determined by player skill, strategy, and teamwork rather than paid progression. The game also features a Brawl mode, in which teams compete on a single lane using randomly assigned heroes in shorter, fast-paced matches, typically played casually or to complete in-game tasks.

Following its success, Moonton has tapped into the esports scene with the creation of several regional tournaments dubbed as Mobile Legends: Bang Bang Professional League (MPL) that serves as a qualifier for the Mobile Legends World Championships from teams worldwide. The game is particularly popular in Southeast Asia and was among the six titles selected for the inaugural esports medal event at the 2019 Southeast Asian Games (SEA Games). It has since continued as a featured title at the 2021 and 2023 editions, and is also confirmed for inclusion in 2025.

Originally titled Mobile Legends: 5v5 MOBA, the game was first released in 2016 and became widely popular, as it was the first fully mobile-based MOBA with no direct competition, albeit not the first of its kind due to being released later than other games such as Vainglory. It however faced some criticism for its perceived similarities to League of Legends, which at the time had no official mobile version. As a result, Riot Games filed lawsuits against Moonton for alleged copyright infringement in 2017 and 2022. While they were awarded some damages, they failed to have the game removed. A 2022 lawsuit in the United States was dismissed, with the court ruling that the case should be heard in China. Ultimately, Riot Games and Moonton reached a settlement in 2024, resolving all intellectual property disputes. In 2020, the game was banned in India along with 58 other Chinese applications after the 2020 China–India skirmishes, although it remains widely played through the use of virtual private networks (VPNs). That same year, the game crossed 1 billion downloads worldwide. In 2025, the game and other apps was briefly affected by the United States' restrictions on TikTok due to its association with ByteDance. The ban has since been lifted in the United States.