California’s labor commissioner has ruled that a driver for Uber Technologies Inc. should be classified as an employee of the company, a decision that marks the latest setback for the ride-hailing company’s labor model.

The ruling doesn’t set a precedent for how Uber compensates its 200,000 drivers, but it is one of a growing number of court decisions that may have far-reaching implications for the company. Uber says its drivers are independent contractors and not employees, a designation that means it isn’t responsible for...