Amazon.com Inc. plans to hire an additional 100,000 employees in the U.S. as millions of people turn to online deliveries at an unprecedented pace and Americans continue to reorient their lives to limit the spread of the new coronavirus.

Amazon plans to deploy the new workers to fuel its sprawling e-commerce machine and is raising pay for all employees in fulfillment centers, transportation, stores and deliveries in the U.S. and Canada by $2 an hour through April. In the U.K., it will go up £2 ($2.45) per hour and approximately...