Oli, who is the son of former Springbok Guy Kebble, was a member of the South Africa U20s side that won the 2012 World Championship.
It will not be his first time in the UK as he previously studied at Dulwich College in London and was part of the London Irish Academy.
After qualifying through residency, the loose-head made his debut for Scotland in October 2020, coming off the bench against Georgia at BT Murrayfield.
He then made his Guinness Six Nations debut against Wales at Parc y Scarlets in the same month, helping the men in blue to a first win in Wales since 2002.