U.S. District Judge Gregory Frost said Tuesday that no one can be put to death before Aug. 15. But his order allows the moratorium to be extended.
Ronald Phillips, who was sentenced to death in 1993 for the rape and murder of his girlfriend's 3-year-old daughter, was scheduled to die July 2. William Montgomery was to be put to death Aug. 6 for killing two young women, Debra Ogle and Cynthia Tincher.
Two more executions were scheduled for later in the year.
Death penalty states have been scrambling to find drugs for lethal injection recently because many pharmaceutical companies refuse to supply them for that purpose. In Ohio's most recent execution, the state used two drugs, the sedative midazolam and painkiller hydromorphone.
Ohio held its last execution on Jan. 16. Witnesses said Dennis McGuire, 53, appeared to be struggling for about 10 minutes while gasping and choking.
Corrections officials announced in April that the doses of both drugs would be increased.