Sealing Jutsu, also known as Fuinjutsu, are special techniques in the Naruto world that help to seal away a target. They are usually used to seal a form of chakra, an object, and sometimes, even humans, along with a host of other things.
These techniques aren't as widely used, but they're known to be extremely dangerous in combat if used properly. Only a few people in the world of Naruto possess a high-level of proficiency with the art of Sealing Jutsu and it has proven to come in clutch in the toughest of battles.
10 Orochimaru
One of the most powerful characters in the world of Naruto, Orochimaru is a shinobi skilled in the ways of every Jutsu, including Sealing Jutsu. He has several powerful techniques up his sleeve, and a glimpse of that was seen during his attempt to destroy Konoha where he sealed away the Kyubi chakra of Naruto.
He's also studied the Uzumaki clan techniques and possesses a great deal of knowledge about their Sealing Jutsu. During the Boruto era, he's possibly progressed even further.
9 Jiraiya
A member of the Legendary Sannin like Orochimaru, Jiraiya was an exceptionally skilled shinobi who was proficient in Ninjutsu, Taijutsu, and even Senjutsu. Although the start of his life as a shinobi was quite shaky, Jiraiya managed to get very powerful and gain a tremendous amount of knowledge with time.
He showed off a variety of sealing techniques in the Naruto series, some of which were powerful enough to seal away a target in the stomach of a Toad, and others that could even seal the inextinguishable black flames of Amaterasu.
8 Kushina Uzumaki
Born in Uzushiogakure, Kushina was brought to Konohagakure to become the next Jinchūriki of the Kyuubi after Mito Uzumaki as she was perfectly compatible with it, thanks to her bloodline.
Being an Uzumaki and a skilled ninja, Kushina is known to have had an incredible hold over Sealing Jutsu. Her strongest known Sealing Jutsu was the Adamantine Chains that could even restrict and seal away a Tailed Beast.
7 Mito Uzumaki
The wife of the First Hokage, Mito Uzumaki possessed the same compatibility with the Kyuubi as Kushina, which is why she was chosen as its Jinchūriki. Mito's mastery over ninja arts was never seen in the story, however, she was likely just as skilled as Kushina Uzumaki due to possessing the same ability.
Furthermore, she was able to seal the Kyuubi within herself, meaning her hold over these techniques was far more refined than that of an average user.
6 Minato Namikaze
Minato Namikaze was the Fourth Hokage of Konohagakure and the man renowned across the world as the Yellow Flash. He was considered to be a prodigy and for him, performing techniques with the ability to seal others wasn't hard at all. Thanks to his wife being an Uzumaki, Minato was able to study the various Sealing Jutsu of the clan.
During the Nine-Tails attack of Konoha, Minato was seen using multiple Sealing Jutsu, such as a Contract Seal, Eight Trigrams Seal, and even the Reaper Death Seal.
5 Obito Uchiha
One of the strongest characters in the entire Naruto series, Obito Uchiha was skilled in all the Ninja arts. His proficiency with Fuinjutsu was down to him having Madara's Rinnegan, with which he could produce the Demonic Statue Chains.
These chains are known to be cursed and weaken anyone that they touch considerably. They are also powerful enough to restrain and seal away all the Tailed Beasts at once. Undoubtedly, Obito was a menacing user of these powers.
4 Madara Uchiha
One of the strongest of the verse, Madara was the only known Uchiha to awaken the Rinnegan in both his eyes and this granted him tremendous powers. When it comes to Sealing Jutsu, Madara got access to the Demonic Statue of the Outer Path, which allowed him to seal away all the Tailed Beasts without any problem.
Furthermore, he was also proficient enough to make himself the Ten-tails Jinchūriki. Other than that, Madara likely had a host of other techniques, like Chibaku Tensei, that he could use to seal his targets away.
3 Naruto Uzumaki
The current strongest shinobi in the world, Naruto Uzumaki is exceptionally skilled in the ways of Ninjutsu and Taijutsu. Thanks to his powers as a pseudo-Ten-tails Jinchūriki, Naruto can access the powers of Shukaku and seal away targets without much of a problem.
Furthermore, he is also a user of the Six Paths: Chibaku Tensei, and when used with Sasuke Uchiha, he could even seal away Kaguya Otsutsuki.
2 Sasuke Uchiha
Sasuke is the strongest shinobi in the world currently, along with Naruto Uzumaki. He's fairly balanced in all the ninja arts, meaning his skill with Sealing Jutsu is just as good as the rest. Sasuke is a user of the Rinnegan which grants him the power to use the Demonic Statue Chains.
What's more, he can use the powers of the Rinnegan to use Chibaku Tensei as well. During the Fourth Great Ninja War, he proved to be strong enough to seal away all nine Tailed Beasts at once. Furthermore, he is also a user of the Six Paths: Chibaku Tensei.
1 Hagoromo Otsutsuki
Hagoromo Otsutsuki, also known as the Sage of Six Paths, is arguably the strongest character in the entire history. Hagoromo was powerful enough to seal away his mother, Kaguya Otsutsuki, with the help of his brother.
He had enough chakra to create a Chibaku Tensei as massive as the moon, which just goes to show that his powers were on a whole different level. Hagoromo also made himself the Jinchūriki of the Ten-tails, again, signifying a great level of control over these powers.