The 21-year-old has penned a five-year deal with CSKA and arrives for €8m plus €1.5m in bonuses.
— ПФК ЦСКА Москва (@pfc_cska) August 25, 2020
Fuchs is one of Brazil’s most promising young talents and made 22 appearances for Internacional’s first team.
CSKA have been scouring the South American market for good deals this summer and Fuchs follows Adolfo Gaich to the VEB Arena.
Argentine international Gaich, 21, joined CSKA from San Lorenzo earlier this month for €8.5m.
The Muscovites have also had a €5m bid for Argentinos Juniors midfielder Fausto Vera rejected.