Madara Uchiha is, undoubtedly, one of the strongest characters in the entire Naruto series. Being the leader of the legendary Uchiha Clan, Madara Uchiha was an exceptionally talented shinobi, the likes of which could only be matched by Hashirama Senju during their era.
Although Madara was already strong, his thirst for power saw him craft an elaborate plan that would ultimately lead to him becoming the 10 Tails Jinchūriki. With tremendous power at his disposal, few could've possibly stood against him in battle and even fewer could've defeated him. Here are 5 characters in Naruto who could defeat Madara Uchiha and 5 who can't.

10CAN DEFEAT: NARUTO UZUMAKI

One of the strongest shinobi to have ever existed, Naruto Uzumaki is one of the few characters in the entire series who could possibly defeat Madara Uchiha. During the 4th Great Ninja War, the two clashed for a long time and Naruto was, more or less, able to keep up with him without any significant problems.
Over the years, Naruto Uzumaki has grown several times stronger and the level on which he is right now sees to it that he surpasses Madara Uchiha in terms of strength. There's no doubt that Madara is an exceptionally powerful character, but Naruto outdoes him in nearly every way.

9CAN'T DEFEAT: TOBIRAMA SENJU

Tobirama Senju was the second Hokage of Konohagakure, taking up the role of the leader following the death of Hashirama Senju. Tobirama was an incredibly powerful shinobi of his time. In fact, he was able to slay Izuna Uchiha in combat pretty easily, showing how powerful he really was.
Even though Tobirama Senju was strong, there was a considerable difference between his and his brothers' powers. Consequently, there was a drastic difference between his and Madara Uchiha's powers as well. Although strong, Tobirama was certainly not powerful enough to defeat Madara Uchiha.

8CAN DEFEAT: SASUKE UCHIHA

Sasuke Uchiha is the strongest known Uchiha to ever exist in Naruto, which makes him stronger than Madara. Sasuke fought Madara Uchiha during the Fourth Great Ninja War and asserted his dominance then. Over the years, Sasuke certainly grew quite a lot and was able to grow to a level where he was equal to Naruto Uzumaki in terms of combat.
Sasuke Uchiha had fought and matched the likes of Momoshiki Otsutsuki in a fight, further solidifying his position on the list. While some fans believe Madara to be the strongest known Uchiha, that's nothing but a misconception and Sasuke is certainly stronger than him.

7CAN'T DEFEAT: ITACHI UCHIHA

ITACHI UCHIHA Naruto
Sasuke's brother, Itachi Uchiha, was just as great a shinobi as Sasuke is today, albeit not nearly as powerful. While Itachi Uchiha was strong in his own right, he certainly wasn't even close to Madara Uchiha's level. With the Six Paths Powers at his disposal, there's absolutely no way for Madara to lose to Itachi, no matter what.
Although some fans believe that Itachi is stronger than Madara Uchiha, there's hardly anything in the series that backs this claim up. Itachi may be powerful, but he definitely doesn't have even a fraction of Madara's godly powers.

6CAN DEFEAT: JIGEN

The undisputed strongest character in the entire Narutoverse, Jigen stands tall as an antagonist that even Naruto Uzumaki and Sasuke Uchiha couldn't defeat. Naruto and Sasuke easily defeated Momoshiki Otsutsuki, and Jigen was much stronger than both of them combined, indicating that Jigen is even stronger than Momoshiki Otsutsuki.
For now, some of Jigen's abilities remain unknown, and we're certain that he'll turn out to be even stronger than what we're imagining him to be.

5CAN'T DEFEAT: KABUTO YAKUSHI

A guy who once claimed to be closest to achieving the power of the Sage of Six Paths, Kabuto Yakushi acquired powers that Orochimaru failed to gain. He was strong enough to fight against Itachi Uchiha during the Great Ninja War, which just goes to show how powerful he really was!
Although defeating Itachi Uchiha could've been possible for him, beating Madara Uchiha was certainly not something that he could've ever achieved in the series. When it comes to Madara Uchiha, the difference in power between the two is just way too massive. Nonetheless, Kabuto could've at least provided a decent fight to Madara.

4CAN DEFEAT: MOMOSHIKI OTSUTSUKI

Momoshiki Otsutsuki is one of the strongest characters in the entire Naruto and Boruto series. Although he might not have been among the strongest initially, once he consumed Kinshiki, his powers grew dramatically. Momoshiki Otsutsuki is, indisputably, someone capable of matching Naruto Uzumaki and Sasuke Uchiha in battle.
He's someone comparable to Kaguya Otsutsuki herself, whose power was said to be several times greater than Madara's. Therefore, Momoshiki Otsutsuki should easily be strong enough to defeat Madara Uchiha. However, it goes without saying that this fight certainly won't be easy for him.

3CAN'T DEFEAT: MIGHT GUY

Might Guy is a master at hand-to-hand combat, and he's proved that countless times throughout the Naruto series. Not only has Guy fought against the likes of Kisame and absolutely decimated them in battle but he's also clashed against Madara Uchiha during the Fourth Great Ninja War.
Using the Eight Inner Gates, Guy was able to overwhelm Madara in a fight, not giving him even an inch. In fact, he nearly killed Madara with his Night Guy technique. Unfortunately, the toll that the Eight Inner Gates take on Guy's body is way too much for him to use this technique for long, and thus, it fell short.

2CAN DEFEAT: HAGOROMO OTSUTSUKI

Hagoromo Otsutsuki is quite easily one of the strongest characters to ever exist in Naruto. Being Kaguya Otsutsuki's son, Hagoromo had great powers that could only be matched by a few characters in the series. He had enough stamina to fight against his mother for months without resting, which shows how insane a monster he truly was!
What's more, his powers further increased after beating Kaguya Otsutsuki, thanks to becoming the 10 Tails Jinchūriki after the events of the war. Hagoromo is someone who Madara Uchiha can't beat, no matter how stronger he gets.

1CAN'T DEFEAT: MINATO NAMIKAZE

Also known as Konoha's Yellow Flash, Minato was a once-in-a-generation prodigy who went on to become the Hokage of the village at a very young age. Using his skills, he was single-handedly able to end the Third Great Ninja War, which goes to show how impressive his abilities were.
Despite all that, Minato's skills are far inferior to Madara Uchiha's and this was proven multiple times during the war. Minato struggled to fight against 10-Tails Obito, therefore beating Madara Uchiha is certainly not possible for him.