Scalia, speaking at a religious event, said the constitutional wall between church and state has been misinterpreted by the Supreme Court and lower courts. As an example, he pointed to a ruling in California that barred students from saying the Pledge of Allegiance with the phrase "one nation under God."
That appeals court decision is on hold pending further consideration by the same court, but the Supreme Court eventually could be asked to review it.
Scalia said rulings by his own court gave the judges in the pledge case "some plausible support" to reach that conclusion.
However, the justice said he believes such decisions should be made legislatively, not by courts.