A federal appeals court ruled in favor Tuesday of a transgender Gloucester High School student seeking to use the boys’ restrooms at the school.

The student, Gavin Grimm, was born female but identifies as a male. He filed a federal lawsuit against the Gloucester County School Board after it passed a policy restricting restroom and locker room use to biological genders while making alternative, single-stall restrooms available for students seeking additional privacy.

Grimm’s suit, filed on his behalf by the ACLU, claimed the policy violated Title IX and the Constitution’s 14th Amendment. It also asked for a preliminary injunction that would allow him to use the boys’ restrooms until the suit is decided.

In a hearing last fall, Federal District Court Judge Robert Doumar denied the injunction and dismissed the claim that the policy violated Title IX. Grimm appealed both decisions and asked that another judge be assigned to hear the lawsuit.

The appeal was heard...