Since the beginning of Dragon Ball Z, Gohan's power was teased whenever his emotions got the better of him. Most famously, he gave Raditz a fierce headbutt for torturing Goku. Years later after some training, he became the first Super Saiyan 2 during his fight against Cell, making him the strongest Z-Fighter at the time. Unfortunately for many Dragon Ball fans, this was the start of Gohan's decline, since he neglected his training in pursuit of academics after this point. Old Kai helped him awaken his dormant power once again, only for him to lose it by the time Dragon Ball Super got underway.
Currently, he's back on top, having reawakened his Hidden Potential just in time for the Tournament of Power with no sign of regressing back into a weakling who can't even go Super Saiyan and loves eating soft serve after work. He's one of the strongest guys around, but the fact that there are so many more people out there whose power dwarfs his own means that he's still got a lot of training ahead of him.
10 Hit
Unlike most Dragon Ball characters, Hit lacks attacks capable of destroying planets and creating huge craters. Because he specializes as an assassin, Hit's techniques are more focused on striking an opponent fast and efficiently, resulting in a swift, nondescript death.
During his first fight with Goku, he improved his Time Skip to rival Goku's x10 Super Saiyan Blue Kaio-ken. Gohan wouldn't be able to see through Hit's Time Skip, especially since he's never been on the receiving end of his blows.
9 Fused Zamasu
Fused Zamasu was so powerful that he was able to handle two Super Saiyan Blues at the same time, shrugging their attacks off like it was nothing. He pushed Goku, Vegeta, and Future Trunks to their limits with his large-scale attacks and durable physical body.
While Gohan proved that at his maximum, he can trade a few punches with a Super Saiyan Blue, he's not stronger than one just yet, and against Fused Zamasu, he would find himself completely overwhelmed.
8 Anilaza
While Universe 3 didn't have any standout fighters like some other universes had, their ace-in-the-hole came in the form of Anilasa, the chaotic fusion of four Universe 3 warriors that on their own, didn't amount of much.
Agnilasa was so powerful that his Full Power Energy Ball was able to contest with the beams of Ultimate Gohan, Golden Frieza, Super Saiyan Blue Goku and Vegeta, and Android 17 combined. If Agnilasa were able to pressure five of Universe 7's strongest mortals, there's no question that his power far exceeds any one of theirs.
7 Toppo
During the Tournament of Power, Gohan had to work alongside Android 17 just to put some pressure on Toppo, and even then, their joint effort proved unsuccessful. Toppo took a direct Ultimate Kamehameha from Gohan without a scratch to show for it.
Even if Gohan somehow managed to gain the edge on him, the moment he decided to tap into his God of Destruction powers would widen the gap between them to a point where it would be impossible for Gohan to catch up.
6 Kefla
Dragon Ball Super's manga and anime contain very different plot points, despite telling a story with the same arcs and major villains. In the anime, Gohan and Kefla never interacted at all, and yet in the manga, they actually ended up knocking one another off the Tournament of Power arena. In the manga, she overwhelmed Gohan at the start of their fight, but he grew stronger the longer they exchanged blows.
What the manga failed to acknowledge was that in being the combination of two highly talented Saiyans that evolved much faster than any other Saiyans seen in the series, Kefla should've progressed at a quicker rate than Gohan did during their battle. In the anime, she was able to push Goku to Ultra Instinct Sign, and even when he utilized this powerful technique, she still proved to be a challenge for him. She's definitely stronger than Gohan, although it's clear that if he were to train for just a little longer, he'd be able to surpass her in no time.
5 Android 17
Android 17's return in Dragon Ball Super was something that some fans were able to predict due to Dragon Ball Super often referencing past characters and events from prequel series. However, no one could've predicted he'd be so powerful. Android 17 showed the capacity to trade blows with god-level opponents like Super Saiyan Blue Goku, Toppo, and Jiren, and the fact that he wasn't subject to fatigue in the same way other warriors were meant that he could get back up from a brutal beating when other warriors would've been down for the count.
He and Gohan are probably close in strength, but Android 17's barriers and infinite energy would give him the immediate advantage if the two were ever forced to go up against one another.
4 Frieza
There's no question that Frieza is several times stronger than Gohan. Gohan's Potential Unleashed form might grant him powers surpassing those of a Super Saiyan 3, but Frieza's Golden Form makes him a god-tier warrior.
He showed the ability to manipulate a God of Destruction's (albeit a weaker one) Energy of Destruction. Gohan, who hasn't learned how to harness divine ki, wouldn't be able to accomplish anything close to this sort of feat.
3 Broly
Gohan might've had a lot of potential when he was young, but Broly puts that to shame. When he was just a baby, he possessed a power level of 10,000, which was stronger than Goku's base form after he trained with King Kai for the first time. During his first-ever battle, Broly transformed into a Super Saiyan in minutes, intuitively utilizing the form and its power boost without strain.
It's safe to say that Gohan, who isn't stronger than one Super Saiyan God Super Saiyan, couldn't even dream of defeating Broly unless he turned his back on his family, friends, and studies to train during every single second of every single day.
2 Vegeta
Vegeta is undoubtedly stronger than Gohan; his Super Saiyan Blue transformation already gives him the edge, and while Gohan allowed his power to drop as a result of neglecting his training, Vegeta has continued to work hard each and every day.
He has much more experience than Gohan, and his Super Saiyan Blue Evolved transformation was strong enough to punch through Energy of Destruction and nail God of Destruction Toppo with a few good shots, while Gohan's Kamehameha did nothing to the Pride Trooper long before he tapped into these powers.
1 Goku
Back in Dragon Ball Z, Gohan managed to surpass Goku when he became the first Super Saiyan 2 in history during the fight with Cell. This was a momentous accomplishment, although it wasn't long before both Vegeta and Goku mastered this form themselves and Goku later debuted Super Saiyan 3, surpassing his son even more.
Dragon Ball Super saw Ultimate Gohan's return, and while this made him one of the strongest Z-Fighters once again, the match he and Goku had before the Tournament of Power was proof that when both fighters gave it their all, Gohan just couldn't hold a candle to his father. With a bit more training, he definitely has the potential to surpass Goku, but then again, with Ultra Instinct under his belt, Goku will always be in a different league.