MIAMI — A federal appeals court on Wednesday struck down a 2011 Florida law requiring drug tests for people seeking welfare benefits even if they are not suspected of drug use, a measure pushed by Gov. Rick Scott in his first term in office.

The three-judge panel of the United States Court of Appeals for the 11th Circuit, in Atlanta, ruled that the law, one of the strictest in the country, was an unreasonable search because Florida officials had failed to show a “substantial need” to test all people who applied for welfare benefits. Applicants were required to submit to urine tests, a measure that Mr. Scott said would protect children of welfare applicants by ensuring that their parents were not buying and using drugs.

“The state has not demonstrated a more prevalent, unique or different drug problem among TANF applicants than in the general population,” the panel said in its unanimous decision, using an acronym for Temporary Assistance for Needy Families.

Eleven states have passed laws to mandate drug testing since 2011, but most of those differ from Florida’s because they require testing only if drug use is suspected. After the Florida Legislature approved its law, Georgia followed suit. A similar measure was ruled unconstitutional in 2003 by a Michigan Court of Appeals.