"I think the girls ought to play girls and the boys ought to play boys," McMaster said earlier this month. When asked if he meant biological boys, the governor responded, "Are there any other kind?"
Opponents have labeled the bill as "cruel" since it can prevent students who are not elite athletes and looking to fit in from engaging with their fellow students. Supporters say the bill protects female athletes from competing with opponents who may have an unfair advantage having been born male.
"We welcome South Carolina to the growing number of states that have acted to preserve fair competition for all females, whether in grade school or college," said Christiana Kiefer, lawyer for conservative Christian legal advocacy group Alliance Defending Freedom. "When the law ignores biological differences, it’s women and girls who bear the brunt of the harm."
South Carolina is the latest state to take up laws against transgender students, following the footsteps of governors in Arizona, Oklahoma and Tennessee.
South Carolina lawmakers have not yet considered stronger laws against transgendered children, such as Texas Gov. Gregg Abbott’s measure that would put such children in foster care.
McMaster also signs the law after a federal district court temporarily blocked the enforcement of two Biden mandates that would force both nonprofit and for-profit religious employers and healthcare providers to pay for and perform transgender medical procedures and counseling.
District Judge Daniel M. Traynor of the U.S. District Court of North Dakota ruled that the Christian Employers Alliance "has shown a likelihood of success on the merits" in its case.
"No government agency ought to be in the business of evaluating the sincerity of another’s religious beliefs," Traynor wrote.
Fox News' Tyler O'Neill and the Associated Press contributed to this report.