"Work hard! Study well! And eat and sleep plenty. That is the Turtle Hermit way! We must master the art of peace in addition to the art of war!" Wise words from the venerable Master Roshi to his students. The turtle hermit played a major role in the original Dragon Ball as he joined Goku on many adventures.
It's hard to become four hundred thirty years old and not pick up some students along the way, right? Learning from Master Mutaito and Korin, the old wisened fighter passed on much of their knowledge as well as his own to many characters throughout the series.
7 Yajirobe
It may have not been a traditional training like some of his other students received, but Yajirobe once worked with the turtle hermit as well. During Dragon Ball Super, Master Roshi finally overcomes his weakness to cute girls with the help of Puar's transformation abilities. After this, he heads to Korin Tower and spars with Yajirobe.
The fact that this usually hapless samurai was able to keep up during these battles is beyond impressive and shows he must have learned a thing or two from the venerable master. That or Korin gave him a ton of senzu beans. Either way, it makes us wonder just how strong is Yajirobe actually?
6 Goku
The most famous of all of his students, Goku still wears Master Roshi's symbol on the back of his gi to honor his original master. His signature Kamehameha came from the turtle hermit as did all of the basics of his fighting techniques. Every opponent Goku has defeated was in part thanks to Master Roshi.
Under the alias of Jackie Chun, Master Roshi fought Goku in the World Martial Arts Tournament to make sure he always felt the desire to continue improving. That work ethic he instilled in Goku has to be one of the major reasons he has been able to train as much as he does and overcome such astronomically powerful opponents to this day.
5 Ox-King
Before the events of the manga even took place, Ox-King was training with Master Roshi. At some point after his training, he got married, became the ruler of Fire Mountain, had Chi-Chi, and then managed to set the entire mountain up in flames.
If anyone doubts how much Master Roshi's training benefited Ox-King, they should know that King Piccolo saw him as a threat. He makes sure some of King Furry's guards are sent to kill him as one of the strongest martial artists on the planet. He may not be able to use the Kamehameha, but he makes up for it with immense strength.
4 Oolong
To be fair, if Master Roshi has taught Oolong anything it's the "eat and sleep plenty" part of the Turtle Hermit Way. The two never train together in any serious way, in fact, he refuses to help him train in Dragon Ball Super, but the two have spent so much time together throughout the series after Oolong moves into his island home.
Oolong must have at least learned some cleverness from Master Roshi as well as he is one of the few people to survive in the alternate future timeline that Trunks travels from after the Androids kill Goku. His rock paper scissors skills could use some work though considering his devastating loss against Beerus.
3 Krillin
Outside of Master Roshi, Krillin is likely the strongest human on planet Earth. He learned much from his master during their time training together and even managed to be a solid rival to Goku during that era. He certainly learned more from the turtle hermit than he did at the Orin Temple where he was raised.
He's died plenty of times against some of the most terrifying villains in the series but has also managed to use his cunning to win battles no one would expect. Considering he beat Goku in a fair fight in Dragon Ball Super, it's impossible for anyone to deny his skills as a fighter. Skills he gained thanks to Master Roshi's training.
2 Yamcha
Yamcha was able to learn a lot from his training with Master Roshi despite having far less time to do so than Goku and Krillin. When he unleashed the Kamehameha in his battle against Tien during the World Martial Arts Tournament it showed he was more than just his Wolf Fang Fist. He might only be a baseball player today, but those lightning-fast reflexes he uses in games were honed during his time with the turtle hermit.
1 Grandpa Gohan
It's a touching moment to realize that Grandpa Gohan helped deliver milk with Master Roshi when he was young just like Goku does as a child. Seeing him hold his own during a match against Goku while wearing a mask shows just how strong of a martial artist he is.
A lot of people have wondered why he was never revived by the Dragon Balls even though this was addressed in the manga. Apparently, the afterlife has a lot of "babes" and Grandpa Gohan is enjoying his time there. He's a student as pervy as his teacher, who could have known?