Home affairs, immigration, safety and security minister Albert Kawana has tabled an amendment bill to replace the current Marriage Act 25 of 1961.
The bill clearly stipulates that spouses may only be from the opposite sex.
This will make same-sex marriages in Namibia illegal.
Kawana tabled the bill in the National Assembly on Tuesday.
The bill reads: "'Spouse' means a person, whether male or female, who is married to a person of the opposite sex and includes such person who is a party to a foreign marriage."