The ruling comes days after the U.S. Supreme Court sided with a Colorado baker who refused to make a wedding cake for a same-sex couple. The high court found Monday that a Colorado civil rights commission showed anti-religious bias when it ruled against Jack Phillips for refusing to make the cake at his Masterpiece Cakeshop.
The decision, however, did not address the larger issue of whether a business can invoke religious objections to refuse service to gay and lesbian people.
In the Arizona case, the state Court of Appeals sided with the city in a lawsuit first brought in 2016 by a wedding invitation business, saying the ordinance is constitutional and does not violate freedom of religion or speech.
"We have previously found that eliminating discrimination constitutes a compelling interest," Judge Lawrence Winthrop wrote, adding that "antidiscrimination ordinances are not aimed at the suppression of speech, but at the elimination of discriminatory conduct."
The court said if Joanna Duka and Breanna Koski, owners of Brush & Nib Studio, "want to operate their for-profit business as a public accommodation, they cannot discriminate against potential patrons based on sexual orientation."
Attorney Jonathan Scruggs of Alliance Defending Freedom, who represented the women, said they intend to appeal the decision to the Arizona Supreme Court.
"Artists shouldn't be forced under threat of fines and jail time to create artwork contrary to their core convictions," Scruggs said in a statement. "The court's decision allows the government to compel two artists who happily serve everyone to convey a message about marriage they disagree with."
The three-judge panel said a stationery store that includes the customized design of wedding event merchandise is not "entitled to First Amendment free speech protections."
"The case before us is one of a blanket refusal of service to the LGBTQ community," the judges said.
Phoenix expanded the ordinance in 2013 to include protections against discrimination and bias based on sexual orientation and gender identity.
Duka and Koski, who are devout Christians, preemptively asked for an injunction barring the ordinance's enforcement. Last October, a trial judge rejected their challenge.
Phoenix Mayor Thelda Williams applauded the ruling Thursday. "We will continue to be a city that welcomes everyone, and value each of our residents regardless of who they love," she said in a statement.
The American Civil Liberties Union, which served as co-counsel for Phoenix, also praised the ruling.
"This decision in Arizona helps affirm that discrimination has no place in businesses open to the public, nor in our Constitution," said ACLU attorney Joshua Block.
In its analysis, the Arizona court referenced the outcome of the Colorado case.
"There is no evidence in the record to support any suggestion that Phoenix's adoption of (the ordinance) or its interpretation as it relates to Brush & Nib, has been anything other than neutral toward and respectful of their sincerely-expressed religious beliefs."