The Leader of the Opposition in South Africa is the leader of the largest political party in the National Assembly that is not in government. The House of Assembly was the most important House from 1910 to 1994 and the National Assembly from 1994. The leader of the opposition acts as the public face of the opposition, leading the Official Opposition Shadow Cabinet and the challenge to the government on the floor of Parliament. They thus act as a chief critic of the government and ultimately attempt to portray the opposition as a feasible alternate government.

John Henry Steenhuisen is a South African politician who has served as the twentieth leader of the Opposition since October 2019 and has been the leader of the Democratic Alliance since November 2020, having served as the interim leader for one year from November 2019. He was chief whip of the official opposition from May 2014 until October 2019.