The iPhone maker said on Monday that Ternus will take over on September 1, while Cook will become executive chairman.

The leadership change comes as Apple strengthens its focus on artificial intelligence, responding to competition from companies including Nvidia, Meta and Google.

Ternus joined Apple in 2001 and currently serves as senior vice-president of hardware engineering. He has worked on several of the company’s biggest products, including the Mac, iPad and AirPods.

He is also seen as an important figure in improving Mac sales in recent years, helping the product regain momentum against personal computer competitors.

Although he has kept a lower public profile than some Apple executives, the company has recently given him a more visible role.

Last year, Ternus presented the iPhone Air, a major redesign of Apple’s flagship device and one of the biggest changes to the product line in years.

At 50, he takes over at the same age Cook did when he succeeded Apple co-founder Steve Jobs in 2011.

Cook leaves the chief executive role after overseeing one of the most successful periods in Apple’s history. Since taking charge in August 2011, he has helped increase the company’s market value by about $3.6 trillion.

He was widely credited with expanding Apple’s global supply chain, especially through manufacturing partnerships in China, while also growing the company’s services and hardware businesses.

Cook also became the first Fortune 500 chief executive to publicly come out as gay in 2014 and often spoke on issues including workplace diversity and environmental policy.

Apple said Cook will remain involved in dealing with policymakers as executive chairman.

Ternus now inherits a company under pressure to show stronger progress in artificial intelligence.

Although Apple introduced Siri in 2011, it has struggled to match the pace of newer AI-focused companies.

Tech giants such as OpenAI and Anthropic have attracted millions of users with new chatbot products, while Nvidia has become the world’s most valuable listed company on the back of demand for AI chips.

In January, Apple reached an agreement with Google to use Gemini technology to improve Siri.

Ternus will also face competition in new devices. Meta Platforms has found success with smart glasses, while Apple’s Vision Pro headset has faced questions over its high price.

Alongside appointing John Ternus as CEO, Apple said Johny Srouji has been named chief hardware officer. He will continue leading the company’s custom chip and sensor teams.

The hardware engineering group previously led by Ternus will now be overseen by Tom Merieb.

The restructuring will see leadership roles reshuffled across its services, hardware, and health divisions.

Eddy Cue, senior vice president of Services, will now oversee Apple’s health and fitness divisions, and this could boost the company’s reported plan to launch a new subscription service, Health+, in 2026. 

The upcoming service is expected to provide personalised coaching across fitness, sleep, nutrition, and mental health, revealing Apple’s goal to turn wellness into a profitable, recurring-revenue business, much like Apple Music or iCloud.

Jeff Williams, who once led Apple’s health initiatives and was important in building the Apple Watch into a health-focused product, handed the COO role to Sabih Khan, formerly vice president of Operations, back in July. With Williams’ exit drawing near, Apple is redistributing his remaining responsibilities. 

According to Bloomberg, software chief Craig Federighi will take charge of watchOS, while hardware head John Ternus will lead Apple Watch engineering, an appointment that analysts see as a strategic nod to Ternus’s potential as a future successor to CEO Tim Cook, who turns 65 next year.

Again, Jay Blahnik, Apple’s fitness chief, will now report to Sumbul Desai, vice president of Health. This comes when an internal probe into the workplace is being conducted. Both executives previously reported directly to Williams. 

The New York Times earlier revealed that Blahnik was sued by a former employee who accused him of enabling a toxic work environment, an allegation that has placed additional issue on Apple’s corporate culture.

Meanwhile, Johnny Srouji, senior vice president of Hardware Technologies, is reportedly “evaluating his future at the tech giant”, months after his team delivered Apple’s first in-house modem, an achievement in the company’s long effort to reduce dependence on Qualcomm.

Sources reveal that Apple’s leadership transition could extend beyond Williams. Other top executives, including Lisa Jackson, who oversees Environment, and John Giannandrea, head of Artificial Intelligence, are rumoured to be considering retirement.