The Indianapolis Star reports that Lynn Starkey worked for 40 years at Roncalli High School until her dismissal earlier this year.
The lawsuit contends that the school subjected Starkey to a hostile work environment, discriminated against her on the basis of her sexual orientation and retaliated against her because of her complaints of discrimination.
In response to the suit, the archdiocese said in a statement that it has the right "to hire leaders who support the schools' religious mission."
Starkey is the second Roncalli guidance counselor to raise discrimination complaints against the school. Shelly Fitzgerald was suspended from her job at the high school because of her same-sex marriage. Fitzgerald has said she intends to sue.
Both women filed charges of discrimination with the Equal Employment Opportunity Commission.
It was Fitzgerald's marriage certificate, pulled by a parishioner of a local Catholic church and turned in to a priest, that sparked the issue of gay married employees within the archdiocese. Suspended last summer, she was the first of four employees in Indianapolis-area Catholic schools to be targeted by the archdiocese.
Starkey was the second. She had worked at Roncalli since 1978. The school chose not to renew her contract; she received a letter notifying her that she would not be offered a contract for the 2019-20 school year, according to the lawsuit. The letter said Starkey's marriage violated her contract and was "contrary to the teaching of the Catholic Church."