Brazilian Jiu-Jitsu is a self-defense martial art and combat sport based on grappling, ground fighting, and submission holds. BJJ approaches self-defense by emphasizing taking an opponent to the ground, gaining a dominant position, and using a number of techniques to force them into submission via joint locks or chokeholds.

Brazilian Jiu-Jitsu was initially developed in 1925 by Brazilian brothers Carlos, Oswaldo, Gastão Jr., George, and Hélio Gracie, after Carlos was taught jiu-jitsu by a traveling Japanese judoka, Mitsuyo Maeda, in 1917. Later on, the Gracie family developed their own self-defense system, and published Gracie Jiu-Jitsu.

BJJ eventually came to be its own defined combat sport through the innovations, practices, and adaptation of Gracie Jiu-Jitsu and Judo, and became an essential martial art for modern MMA.

BJJ revolves around the concept that a smaller, weaker person can successfully defend themselves against a bigger, stronger, heavier opponent by using leverage and weight distribution, taking the fight to the ground and using a number of holds and submissions to defeat them. BJJ training can be used for sport grappling and self-defense situations. Sparring, commonly referred to as "rolling" within the BJJ community, and live drilling plays a major role in training and the practitioner's development. BJJ can also be used as a method of promoting physical fitness, building character, and as a way of life.