Left-arm spinner Peterson will replace Hashim Amla in the current One Day squad in England.
"Considering the tournament takes place on the sub-continent the selection committee has opted for two spinners," Cricket South Africa (CSA) chief executive Gerald Majola said in a statement.
"Having a left and right-arm option in Robin Peterson and Johan Botha gives the selectors the variation they're looking for," he added.
Peterson, who has played in 35 One Day Internationals, last played in the 2007 World Cup in the Caribbean while Botha, who has played 27 times, has featured regularly for South Africa since their run to the semi-finals where they lost by eight wickets to eventual champions Australia.
South Africa, second seeds in the competition, will play England, New Zealand and Sri Lanka in Group B of the competition which begins on September 12th.
The top two teams in the group progress to the semi-finals.