Master Roshi, known in Japanese versions as Kame Sen'nin (Kame Sennin) and Muten Rōshi , is an ancient and wise martial arts master and the first Earthling to wield the Kamehameha. Though he seems frail, he is a mighty warrior, having trained Grandpa Gohan, Ox King, Son Goku, and others. He is a stock character, as he is both the archetypal wise old man and dirty old man, the latter being typical of shōnen manga. Still, he is depicted to be a very wise and gentle person, who loves life and its simple pleasures, but is willing to die if necessary, such as when performing the Mafuba technique (Evil Containment Wave in the English dub) against Piccolo Daimao. He sometimes gets cranky, which further provides comic relief. He is bald, with a thick van dyke beard and wears sunglasses. Roshi wears beach clothes or martial arts suits and, during the earlier stages of the series, a turtle shell on his back. He usually wields a walking stick. When wishing to act anonymously in the World Martial Arts Tournament, Roshi uses the name Jackie Chun.

Roshi's character design was inspired by the character of Kami-sama from Toriyama's previous manga Dr. Slump (who is unrelated to the Kami-sama from Dragon Ball).