A bipartisan group of 15 Hawaii representatives is advocating for a constitutional amendment defining marriage as a union between a man and a woman.
If passed, the amendment would be placed on the ballot during the November 2014 election.
Sen. Mike Gabbard, a Democrat, is proposing a similar bill in the Senate.
A bill to legalize same-sex marriage was also introduced in the House on Thursday. Rep. Faye Hanohano, a Democrat, is the bill's sole sponsor.
Gabbard says that a ballot initiative would be the most democratic way to resolve the issue.
Gabbard is a former Republican who campaigned against promoting homosexuality in the 1990s. He pushed for a constitutional amendment giving the state Legislature the power to limit marriage to a man and a woman. The amendment passed in 1998.