Both All Might and Goku are characters in their world. Goku has saved his world multiple times in the Dragon Ball series while All Might is a character in the world of My Hero Academia. Both of them are widely considered the most powerful characters on their own perspective worlds.

Let’s start with My Hero Academia characters All Might the symbol of peace is a No. hero and probably one of the best bets to give Goku a run for his money like if Goku popped up and said I want to fight your world’s greatest champion. Just because All Might could probably turn coal into diamonds with the force of his sneeze it doesn’t mean that he would emerge victorious because yes almighty is incredibly strong when he uses his one-for-all quirk like we can all picture him in action with the emotional music playing and him rocking that signature smile but the honest truth is that his power levels just don’t match up to Goku sure maybe if Goku didn’t keep powering up to insane new planet busting levels after a certain period of time then the fight would be more even but if all might delivered a devastating Texas smash, While Goku was in Super Saiyan 3 or higher than sorry all might you’ll barely scratch the dude you’re better off fighting a younger version of Goku you know the one that turned into a monkey.

Can All for One even dare to touch fight Goku, time for show’s greatest villain All for One breaks out of prison we don’t need to fear but rather just find a way to call Goku to come beat him because it’s clear that All for One doesn’t stand a chance against the same yes All for One is a scary-looking dude he dresses well and has a weird looking mask on his face and neck that probably haunts a lot of people’s dreams but that doesn’t mean that his power said would be able to beat Goku it all comes down to what quirks All for One has at his disposal the baddies main ability is to steal other people’s quirks to use for himself and although that’s terrifying there’s really nothing that All for One could have stolen that would be a match for Goku the only thing that might be able to overwhelm Goku would be the impact recoil ability which allows the bad guy to reverse the impact of an attack hurting the user instead while this would be good for maybe one attack we could see Goku easily breaking through it with his next punch or blast All for One can’t hide behind his abilities forever and that’s when Goku would over him and take him down.

Winner 

Goku would be the clearly win the fight against All Might. He has better health and strength than All Might, and Goku can heal himself with Senzu beans. Goku is stronger and faster.

With his Super Saiyan abilities, he can quickly make himself even stronger and faster than he would be normally. While All Might is a powerful threat to a quirk carrying villain, he would not stand a chance against Goku. Even with All Might’s ability to outthink the range of Goku, Goku is clearly the greatest fighter between the two.