Master Roshi (武む天てん老ろう師し Muten Rōshi, lit. "Old Heavenly Martial Arts Master"), also known as the Turtle Hermit (亀かめ仙せん人にん Kame Sen'nin) (or Turtle ( Kame) in his youth) and God of Martial Arts (武道の神様 Budō no Kami-sama), is a perverted hermit and a master of martial arts. He lives on his own isolated island called Kame House, where he may be willing to train students who travel to his doorstep. He is also the originator of the Kamehameha Wave.

Despite his lecherous tendencies and his old age, Roshi is an extremely respected and capable warrior, serving as the master of Gohan, Ox-King, Goku, Krillin, and Yamcha. His drive to push his students to new heights and support them on their martial arts journeys makes him one of the most notable supporting characters in the series.

Master Roshi is bald, with a thick white fu manchu mustache and beard. He is almost always seen wearing his trademark sunglasses; sometime later Master Roshi left his old sunglasses and began to wear more futuristic ones. He wears beach clothes or a martial arts suit and a Turtle Shell on his back. He usually wields a walking stick. His bust, waist and hip measurement are all 73cm. When disguised as Jackie Chun, Master Roshi glues a wig of white hair onto his head.

In Dragon Ball Z: Battle of Gods, Master Roshi wears a pink shirt and white shorts with crocs. In Dragon Ball Z: Resurrection ‘F’, Master Roshi wears a white tank top and green flip flops.

When he was a teenager while training under Master Mutaito and Korin, it is shown that he had black hair and wore a black pair of sunglasses along with a bluish-purple Qipao style martial arts uniform. He was also noted by Bulma to be very handsome, shocked to see how Roshi turned out in old age. During the King Piccolo wars, his head was shaven, and he wore a purple Mutaito Training Academy Gi like the rest of Mutaito's students at the time including Master Shen. He also did not wear any sunglasses during this time.

In Dragon Ball Super, Master Roshi wears the pink shirt outfit in the God of Destruction Beerus Saga and the white tank top outfit in the Golden Frieza Saga as he did in the movies.

During the Galactic Patrol Prisoner Saga, while acting as a Deputized Galactic Patrolman, his white shirt similar to the one he wore during the Tournament of Power features the Galactic Patrol symbol.

He generally has a very thin and frail appearance, for all intents and purposes appearing as nothing but an old, worn out senior citizen though this is effectively a disguise - when drawing ki into his body he becomes extremely buff and muscular.