Thole joins the agency from Brunswick, where he worked as a director in its energy and resources practice, focusing on mining clients.
Before Brunswick, Thole was companies editor of Business Day, South Africa's largest financial daily, and worked as a journalist at Mineweb in Johannesburg.
He will work in Pelham's mining team, alongside founding director Charles Vivian and associate director Lorna Spears.
Meanwhile, Vela has been promoted to manage the centralised comms and new business function of Bell Pottinger Private. She joined the agency in February from The Spectator.