British-born Ive joined Apple in 1992 and designed the iPod, iPhone, iPad and Macbook.
Apple announced Thursday its star design chief Jony Ive, who played a key role in the development of the iPhone and other products, was leaving to set up his own firm.
Ive will depart later this year "to form an independent design company which will count Apple among its primary clients," Apple said in a statement.
Ive will pursue "personal projects" but also continue to work closely "on a range of projects with Apple," the California tech company said.
"Jony is a singular figure in the design world and his role in Apple's revival cannot be overstated, from 1998's ground breaking iMac to the iPhone and the unprecedented ambition of Apple Park, where recently he has been putting so much of his energy and care," said chief executive Tim Cook.
"Apple will continue to benefit from Jony's talents by working directly with him on exclusive projects, and through the ongoing work of the brilliant and passionate design team he has built.
"After so many years working closely together, I'm happy that our relationship continues to evolve and I look forward to working with Jony long into the future."
British-born Ive joined Apple in 1992 and designed the iPod, iPhone, iPad and Macbook as well as the iOS software system for Apple devices.
Ive was a key collaborator of the late Steve Jobs at Apple when the company's fortunes were revived with the development of the iPod and later the iPhone.
In Walter Isaacson's biography, Jobs praised Ive as being his partner in dreaming up devices.
"If I had a spiritual partner at Apple, it's Jony," Jobs was quoted as saying.
"Jony and I think up most of the products together and then pull others in and say, 'Hey, what do you think about this?'"
"After nearly 30 years and countless projects, I am most proud of the lasting work we have done to create a design team, process and culture at Apple that is without peer," Ive said in Thursday's statement.
"Today it is stronger, more vibrant and more talented than at any point in Apple's history."
Apple said its design team leaders Evans Hankey and Alan Dye will report to Jeff Williams, Apple's chief operating officer.
Ive said the design team "will certainly thrive under the excellent leadership of Evans, Alan and Jeff, who have been among my closest collaborators."