Fitzgerald claims the decision was discriminatory. She is seeking damages for emotional distress and the loss of wages.
David Page, Fitzgerald's lawyer, argued in the lawsuit that his client was treated differently than heterosexual employees who have disobeyed other Catholic teachings.
The archdiocese has been embroiled in controversy in recent months over the subject of school employees in same-sex civil marriages.
Employment contracts in the Archdiocese of Indianapolis require teachers, whom it says are ministers of the Gospel, to “convey and be supportive of all teachings of the Catholic Church.”
A Jesuit high school in the archdiocese, Brebeuf Prep, appealed to the Vatican after the archdiocese revoked its Catholic status when it would not terminate an employee in a same-sex civil marriage. That appeal is still pending.
In August, Joshua Payne-Elliot, a teacher dismissed from Cathedral High School in Indianapolis, filed suit after he was dismissed for contracting a same-sex civil marriage.
“The Supreme Court has repeatedly recognized that churches have a constitutional right to determine rules for religious schools, and that religious schools have a constitutional right to hire leaders who support the schools’ religious mission,” Jay Mercer, an attorney for the archdiocese, said in August.
“Families rely on the Archdiocese to uphold the fullness of Catholic social teaching throughout its schools, and the Constitution fully protects the Church’s efforts to do so.”
In September, the federal Department of Justice backed the school’s decision in the Payne-Elliott case.
“This case presents an important question: whether a religious entity’s interpretation and implementation of its own religious teachings can expose it to third-party intentional-tort liability. The First Amendment answers that question in the negative,” a the DOJ statement said.
In June, the archdiocese said of teachers that “it is their duty and privilege to ensure that students receive instruction in Catholic doctrine and practice. To effectively bear witness to Christ, whether they teach religion or not, all ministers in their professional and private lives must convey and be supportive of Catholic Church teaching.”