Zuma, who has been in power since 2009, faces numerous allegations of corruption.
His resignation came at the end of a long speech in which he said he disagreed with the way the ANC had acted towards him.
According to BBC, he said he did not fear a motion of no-confidence, adding: "I have served the people of South Africa to the best of my ability."
"No life should be lost in my name and also the ANC should never be divided in my name. I have therefore come to the decision to resign as president of the republic with immediate effect," he was quoted as saying.
"Even though I disagree with the decision of the leadership of my organisation, I have always been a disciplined member of the ANC.
"As I leave I will continue to serve the people of South Africa as well as the ANC, the organisation I have served... all of my life."
Meanwhile, the ANC said Zuma's resignation provided "certainty to the people of South Africa".
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)