Ramaphosa, a former trade unionist and wealthy businessman, is expected to announce the election date in February.
At the last national elections, held in 2014, the African National Congress won 62 percent of the vote, the DA won 22 percent and EFF took six percent.
An October poll by Afrobarometer suggested 48 percent of South Africans would vote for the ANC, with the DA and EFF tied on 11 percent each.
South Africans will head to polls in May 2019, officials said Wednesday, with President Cyril Ramaphosa and the ruling ANC party seeking to reverse growing voter discontent over the weak economy.
The ANC, which has held power since the end of apartheid in 1994, recorded its worst electoral performance in local polls in 2016 before it replaced scandal-tainted Jacob Zuma with Ramaphosa earlier this year.
The main opposition Democratic Alliance (DA) and radical Economic Freedom Fighters (EFF) parties will hope to make gains in the election as unemployment hits record highs of near 28 percent and racial inequalities remain dire.