The US rapper, known as Ye, was accused of violating the platform's rules prohibiting incitement to violence.
He has not posted anything new since returning to the site, which owner Elon Musk has rebranded to X.
Ye's account now shows his last post on 1 December 2022, a day before it was was suspended.
Musk said at the time that Ye had "violated our rule against incitement to violence", and that the account would be suspended.
It came after the musician posted a series of offensive tweets - one of which appeared to show a symbol combining a swastika and the Star of David.
The suspension followed a similar ban two months earlier, when Ye was initially locked out of his Twitter and Instagram accounts after posting anti-Semitic messages in October. Both platforms removed his posts.
In the same month, clothing giant Adidas cut ties with the rapper, saying it did "not tolerate anti-Semitism and any other sort of hate speech".
Ye was also suspended from Instagram for 24 hours in March last year after using a racial slur in reference to comedian Trevor Noah.
Neither X or its billionaire owner Mr Musk have commented publicly on Ye's account reinstatement on Saturday.
Musk reinstated former US President Donald Trump's account last November after conducting a poll with 51.8% voting in favour of the reinstatement.
Trump said he had no interest in returning to the site.