The Nigeria international joins Stellenbosch on a free transfer after spending the last four-and-a-half seasons with the Buccaneers.
"Olisa is a player with proven quality and experience at the highest level, and we are pleased to welcome him to Stellenbosch FC," the club's CEO Rob Benadie said.
"We are deliberate in our recruitment strategy to ensure that every signing complements the group, and having had the chance to assess him closely, we are confident he will be a valuable addition to our squad."
Ndah will become the fourth Nigerian player to represent Stellenbosch, alongside new teammates Ibraheem Jabaar and Kazie Enyinnaya, and former Maroons forward Stanley Dimgba.
He will wear the No. 99 jersey and could be in line to make his Stellenbosch debut they take on Magesi FC in a Betway Premiership encounter on Wednesday at Danie Craven Stadium.
Orlando Pirates coach Abdeslam Ouaddou says he has been mentality preparing for his side's crucial upcoming Betway Premiership clash with title rivals Mamelodi Sundowns for the past two weeks.
Marumo Gallants have announced a temporary change of venues for their home Betway Premiership from the Dr Petrus Molemela Stadium to the Lucas Moripe Stadium.
Orlando Pirates and Mamelodi Sundowns will headline this week's Betway Premiership action when they meet at the FNB Stadium in Johannesburg on Wednesday in a clash that could shape the title race.
Stellenbosch will host Magesi FC at the Danie Craven Stadium on Wednesday in a Betway Premiership fixture that could prove pivotal in the battle for top-flight survival.
