A shop in Maryland will be the first US retail branch of IT giant Apple to form a labor union.
About 100 of the 110 staff at the store in a shopping center in the eastern state voted on Wednesday through Saturday.
Sixty-five were in favor while 33 were opposed. The workers are said to be demanding pay raises and improved measures to prevent coronavirus infections.
US media say Apple shop workers in New York, Georgia and Kentucky are also seeking to unionize.
Workers in the country are growing increasingly dissatisfied with harsh working conditions due to a labor shortage caused by the restart of economic activities after the pandemic.
Employees at Starbucks, and Amazon's distribution centers are also seeking to unionize.