The signing was initially delayed because Real Madrd have a limited number of non-EU passport holders that they can incorporate into the side.
It was also reported that Vinicius Jr is awaiting Spanish citizenship and that the right back position is also a position that needs strengthening.
Vinicius only signed for Shakhtar in January, but was unable to debut for the Ukrainians due to the conflict with Russia.
FIFA since allowed players in the Ukrainian league to move outside of the winter window, permitting Real Madrid to make their move.
Shakhtar Donetsk confirmed that Vinicius Tobias has signed for Real Madrid. The 18-year-old Brazilian full back joins Los Blancos on loan until the end of the season and will play for Castilla.
Real Madrid have the option to make the signing of Vinicius permanent should they impressed with his performances in the reserve side.
