WASHINGTON—A conservative-leaning U.S. appeals court in Cincinnati was randomly selected Tuesday to decide challenges to the Biden administration’s new rules requiring many employers to ensure their workers are vaccinated or tested weekly for Covid-19.

Legal challengers have petitioned federal appeals courts around the country to review the rules, formally issued earlier this month by the Occupational Safety and Health Administration. The requirements, which apply to businesses with 100 or more employees and cover roughly...

WASHINGTON—A conservative-leaning U.S. appeals court in Cincinnati was randomly selected Tuesday to decide challenges to the Biden administration’s new rules requiring many employers to ensure their workers are vaccinated or tested weekly for Covid-19.

Legal challengers have petitioned federal appeals courts around the country to review the rules, formally issued earlier this month by the Occupational Safety and Health Administration. The requirements, which apply to businesses with 100 or more employees and cover roughly 84 million workers, are scheduled to take effect Jan. 4.

Some challengers, including Republican-led states and some employers, have said the rules were unlawful government overreach. Others, including labor unions, said the rules didn’t go far enough.

The U.S. Judicial Panel on Multidistrict Litigation conducted a random lottery Tuesday to determine which of the nation’s 12 regional appeals courts would be the designated home for the cases. The winner drawn was the Sixth U.S. Circuit Court of Appeals in Cincinnati, one of the more conservative U.S. appeals courts.

The lottery outcome means that another appeals court that has thwarted a number of Biden administration initiatives—the New Orleans-based Fifth Circuit—will have to cede control of cases filed before it. The Fifth Circuit had already issued a preliminary stay blocking the employer rules for now, before it was decided which court would retain jurisdiction on the matter.

The Fifth Circuit in a Friday ruling said the Biden rules exceeded OSHA’s powers and would create economic upheaval. The administration argued its rules were on solid legal footing and a necessary step to prevent coronavirus transmission in America’s workplaces.

With a court assignment now completed, the Justice Department can ask the Sixth Circuit to lift the Fifth Circuit’s stay. The matter could quickly land on the Supreme Court’s emergency docket before the vaccine-or-testing requirement takes effect.

Employers who don’t comply with the requirements could face penalties of up to around $13,600 per violation. The requirements don’t apply to employees who don’t report to a workplace where other people are present, employees who only work from home or employees who work exclusively outdoors.

Write to Brent Kendall at brent.kendall@wsj.com