Doug Field, who stepped down as the senior vice president of engineering at Telsa last month, is returning to Apple, Apple told Reuters on Thursday.
Field will be working with Apple executive Bob Mansfield, who has been heading up Apple's self-driving car program, Project Titan. Field and Mansfield previously worked together on engineering Apple's line of Mac computers.
Field has spent the past five years at Tesla. In April, Tesla Chief Executive Elon Musk said in a tweet that he had asked Field to manage the company's engineering and production while Musk focused more time on Model 3 production.
But in May, reports emerged that Field was leaving the carmaker, which has raced to meet production targets for the Model 3. At the time, Tesla said Field was "just taking some time off to recharge and spend time with his family. He has not left Tesla."
Apple has said little about the scope of its self-driving car project, but court documents filed last month said that as many as 5,000 people were authorized inside the company to access information about the project.