American Kenpo Karate (/ˈkɛnpoʊ/), also known as American Kenpo and Kenpo Karate, is an updated system of martial arts based on modern-day street fighting that applies logic and practicality. It is characterized by the use of quick and powerful strikes delivered from all of the body's natural weapons, powered by rapid stance transitions, called "shifting." Beginners are introduced to basic attack responses, which comprise a larger system taught through scripted scenarios, which allow instructors a platform to share concepts and principles Ed Parker emphasized in his teachings.

The purpose of training in this manner is to increase physical coordination and continuity with linear and circular motion. Each movement, when correctly executed, leads into the next, keeping an adversary's "dimensional zone" in check, while limiting their ability to retaliate. Should the adversary not react as anticipated, the skilled Kenpo practitioner, it is argued, is able to seamlessly transition into an alternative and appropriate action, drawn spontaneously from the trained subconscious.

Founded and codified by Ed Parker, American Kenpo is primarily a self-defense combat system. Parker made significant modifications to the original art of Kenpo which he learned throughout his life, by introducing or changing principles, theories, and concepts of motion, as well as terminology. At the time of his passing in December 1990, Parker had created Short Form 1, Long Form 1, Short Form 2, Long Form 2, Short Form 3, Long Form 3, Long Form 4, Long Form 5 (Surprise Attacks), Long Form 6 (Bare Hands vs. Weapons), Long Form 7 (Twin Clubs), and Long Form 8 (Twin Knives). Parker also created 154 named (ideal phase) technique sequences with 96 extensions, taught in three phases (Ideal, What-if and Formulation Phases). Parker believed in tailoring Kenpo to the individual and would also encourage his students to explore the unknown areas of martial arts.

Parker left behind a large following of instructors who honored his teachings by implementing many different versions of American Kenpo. As Senior Grandmaster, Parker did not name a successor to his art, but instead entrusted his senior students to continue his teachings in their own way.

American Kenpo emphasizes lightning fast techniques to destroy an attacker in seconds. Kicks are less common, and usually directed at the lower body because high kicks are slower to execute and potentially compromise the practitioner's balance, higher kicks are taught to more advanced and capable practitioners. American Kenpo contains a wide array of kicks, punches, open-hand, elbow and knee strikes, finger strikes, some throwing and joint locking techniques, as well as club and knife training. The mountain of motion and principles are available, but after learning the basics students specialize in whatever areas fit their needs and desires. A soldier may emphasize knife techniques, a police officer may emphasize locks and stick techniques, a civilian interested in competition may emphasize the less lethal options, while some specialize in the more lethal aspects of the system.

Physically, American Kenpo develops environmental awareness, structural stability, balance, coordination, flow, speed, power and timing in that order as the student progresses through a step by step curriculum. Memorization of the system is not necessary to gain functional skill and is primarily for students who wish to become instructors. All American Kenpo students are taught not only how to execute each basic movement in the system, but also when and why to execute each basic movement. Senior Grand Master Ed Parker placed emphasis on concepts and principles over sequences of motion. He did not want his students to mimic him but rather to tailor his American Kenpo system to their own circumstances and needs. Thus American Kenpo is not a traditional art but a combat science that is designed to evolve as the practitioners' understanding improves. This also placed the burden of effectiveness on the individual practitioner. It was up to them to make their American Kenpo applications effective by correctly applying the concepts and principles to the instructor's ideal phase techniques.

Students are encouraged to formulate a logical sequence of action that removed the dangers of what-if scenarios, effectively turning a what-if problem to an even-if solution. Every American Kenpo black belt will have their own unique and tailored style, but Parker published minimum requirements for each belt rank that instructors in his association - the IKKA - were to follow. However, if a Kenpo Instructor starts his own association, he or she is free to select his or her student's base curriculum as they see fit.

The modern history of American Kenpo began in the 1940s, with James Mitose (1916–1981). Mitose was only one of the many people that Ed Parker's Kenpo Instructor William K. S. Chow worked with. William K. S. Chow, aka Professor Chow, aka Thunderbolt Chow. Professor Chow and his teacher, Thomas Young, handled much of the teaching of the Martial Arts and James Mitose advertised the club and set up demonstrations. However, Professor Chow thought of Mitose as "a con-artist who was all talk" and went off to teach on his own. Mitose was never a teacher of Ed Parker, and thus had no part in American Kenpo.

William Chow claimed to have studied multiple Martial Arts in Hawaii, including Chinese Kung Fu (Shaolin) from his father.Chow eventually developed Kenpo Karate, which had a blend of linear and circular motion, and emphasized practical fighting techniques designed to outperform the various martial arts in the melting pot of Hawaii.[9][10] Chow experimented and modified his art, adapting it to meet the needs of American students.

The legendary Ed Parker, dubbed "The Magician of Motion", started his martial arts training in Judo, earning a black belt. He then studied western boxing from his father, a boxing commissioner in Hawaii, before eventually training and earning a black belt from William Chow in Kenpo Karate. After Ed Parker moved to California, he cross-referenced his martial arts knowledge with Chinese martial arts masters in China. Parker hosted a large martial arts tournament, the Long Beach Internationals, where he used his analytical mind to study the attending martial artists and improved his own system, eventually founding American Kenpo. Ed Parker founded his own Kenpo association, The International Kenpo Karate Association (IKKA), after his students started teaching his art in other countries.Al Tracy claims that Chow promoted Parker to sandan (3rd-degree black belt) in December 1961.

Senior Grandmaster Ed Parker called his art American Kenpo. He started teaching other Hawaiian Islanders attending Brigham Young University in Provo, Utah in 1954. By 1956, he was teaching commercially in Provo.[12] Late in 1956, he opened a studio in Pasadena, California.He published a book about his early system in 1960.[11] The book has a heavy Japanese influence, including the use of linear and circular movements, "focused" techniques and jujutsu-style locks, holds, and throws. When Parker increased the Chinese arts content of his system, he began to refer to his art as Chinese Kenpo. Based on this influence, he wrote Secrets of Chinese Karate,published in 1963.

The system which came to be known as American Kenpo was developed by Parker as his Specific System, and featured Parker's revisions of older methods to work in more modern fighting scenarios.He heavily restructured American Kenpo's forms and techniques during this period. He moved away from methods that were recognizable from other arts (such as forms that were familiar within Hung Gar) and established a more definitive relationship between forms and the self-defense technique curriculum of American Kenpo. Parker also eschewed esoteric Eastern concepts and sought instead to express the art in terms of Western scientific principles and metaphors. During this time, Parker also dropped most Asian language elements and altered traditions in favor of American English.

Ed Parker continually developed his art, causing students to learn different curriculum interpretations and arrangements depending on when they studied with him. Since many instructors had gone their own ways and didn't continue with Parker's updating, Kenpo today has several different versions of techniques. None of the versions is wrong, as long as it works for the individual practitioner. This is what set Parker apart from many traditionalists who wanted to make students into exact replicas of their instructors. American Kenpo should be tailored to fit each individual student by a competent instructor. While Parker was labeled a rebel when he first introduced his revolutionary ideas, they have since been tested and proven by members of the military, law enforcement, and civilians. Many have successfully survived violent situations due to the training they received in American Kenpo. One of the best-known students of Ed Parker was Elvis Presley.