Raja Yoga (translated meaning "Royal Yoga") refers specifically to the system of yoga outlined by Patanjali in his Yoga Sutras.

It is also sometimes referred to as Ashtanga (eight-limbed) yoga because there are eight aspects to the path of meditative introversion that this system requires. Raja yoga is concerned principally with the cultivation of the mind using meditation.

Raja Yoga is an exact science. It aims at controlling all thought-waves or mental modifications. While a Hatha Yogi starts his practice with Asanas (yoga postures) and Pranayama (breath control), a Raja Yogi starts his practice with the mind, although a certain minimum of asanas and pranayamas are usually included as a preparation for the meditation and concentration.