The proposal comes in a green paper from South Africa's Department of Home Affairs and has sparked outrage from conservative voices in the Rainbow Nation.
Polygamy, the practice of men taking multiple wives, is legal and part of some indigenous traditions.
"South Africa inherited a marriage regime that was based on the Calvinist Christian and Western traditions," the paper states, saying that there is a need for an "overarching policy that is based on constitutional values and the understanding of modern society dynamics"
The paper notes that current marriage law is flawed and allows for the marriage of minors and does not allow people to change their sex and remain married.
Human rights activists consulted in the process of writing the file "submitted that equality demands that polyandry be legally recognised as a form of marriage".
Officials say that one option could be a "gender-neutral" regime.
"South Africa could do away with categorising marriages along lines of race, sexual orientation, religion and culture," they suggested.
"That means South Africa (could) adopt a dual system of either monogamous or polygamous marriages."
That would then allow for polyandry, or women taking multiple husbands, due to the "gender-neutral" requirement.
Conservatives have argued that polyandry and polygamy are entirely different.
"Let us defend our culture, tradition and customs by participating in this process. Let us object to Polyandry outright," said reality TV star Musa Mseleku.
Claiming to be "pro-equality", Mseleku questioned how paternity would be determined polyandrous marriages.
"That child is going to belong to which family?" he asked.
Reverend Kenneth Meshoe, the leader of the African Christian Democratic Party, argued that differences between the sexes would spell disaster for such unions.
He said polygamy was "an accepted practice" while polyandry would fail because "men are jealous and possessive".
