The bill submitted by former president Charles Taylor’s ex-wife, now a senator, also seeks to amend laws to prohibit gay marriage.
"No two persons of the same sex shall have sexual relations. A violation of this prohibition will be considered a first degree felony," reads the proposed amendment to marriage laws.
First degree punishment can range from 10 years to life imprisonment to the death sentence, on the discretion of the judge.
Voluntary sodomy is already a criminal offence in the west African country and can result in up to three years imprisonment, according to a lawyer consulted by AFP.
George Tengbeh, a senator supporting the bill, said he hoped it would put an end to months of acrimonious public debate on gay rights.
Umm, someone needs to tell the senator that in democracies, acrimonious public debate does not need to lead to be resolved by death penalty legislation.
It aims "to prevent the parliament from talking about such an issue that is against our tradition and culture," he told AFP.
Right, because the last thing a democracy wants is a discussion. It does look like cooler heads will prevail.
The information ministry released a statement on January 26 saying: "The Liberian government will not allow the legalisation of gay and lesbian activities in Liberia. The president has vowed not to allow such a bill, and even if the bill goes before the president she will veto it."