Utah officials had appealed to the nation's highest court after its attempts to halt same-sex marriage in the state had failed at the district level and in the 10th Circuit Court of Appeals last month.
While Utah's attorney general filed an appeal to the 10th Circuit, both Shelby and the 10th Circuit denied the state's request for an emergency stay, claiming allowing gay couples to marry would cause them harm if the state's ban was later upheld and their marriages invalidated. Utah appealed to the Supreme Court last week.
Monday's decision came without any noted dissents, meaning the court wishes to have the basic constitutional question of whether marriage is between a man and a woman hashed out in the lower courts. Otherwise, allowing Utah's marriages to continue may have indicated the court was willing to allow gay marriage in the 33 states where it is still banned.
Some 1,000 couples have been married in Utah since December 20, when Shelby first declared the state ban unconstitutional.