The six South Florida couples and the Equality Florida Institute filed the lawsuit in Miami-Dade Circuit Court, according to the Tampa Bay Times.
The lawsuit argues that the state's same-sex marriage ban violates the Constitution by denying gay couples "the legal protections and equal dignity that having the freedom to marry provides," according to a press release from the National Center For Lesbian Rights, which is representing the plaintiffs.
A 2008 amendment to the state Constitution defined marriage as being between a man and a woman.
"These couples have been embraced by their families and communities, but every day, Florida laws are denying them the protections and dignity that every family deserves," Equality Florida Institute CEO Nadine Smith said in the release. "These harmful laws are outdated and out of step. It is time for all families in our state to have full equality under the law.”