More than 200 mayors gathered in Dallas for a 4-day conference that ended Monday.
The resolution urging courts to support allowing same-sex couples to marry was among those passed by the group.
In 2009 the conference endorsed the freedom of same-sex couples to marry and reaffirmed that in the current resolution.
The group noted that 19 states and the District of Columbia allow same-sex couples to marry.
The conference also condemned any legislation that authorizes discrimination in employment or refusal of service or facilities to gays and lesbians.
This material may not be published, broadcast, rewritten, or redistributed.