Fatau joins the Peoples’ Elephants on a two-year deal, having agreed personal terms.
The 31-year-old has played in South Africa with Orlando Pirates and Chippa United and represented the Black stars at the Africa Cup of Nations in 2008 and 2013.
Enyimba are left with just 1 senior goalkeeper Theophilus Afelokai following the exit of Femi Thomas, Moses Ocheje and a former U-17 stopper, Joshua Enaholo.
The Aba giants also signed defender Tijani Joshua from Ghanaian club Ashanti Gold.
Enyimba will take on Sunshine Stars on January 15th in their Match Day 1 fixture of the new league season.