O'Brien was most recently Apple's VP of Worldwide Sales and Operations and has spent nearly 30 years with the company.
She'll oversee all HR functions including talent development, recruiting, benefits, compensation, and business support, as well as managing Apple University.
"As long as I've been at Apple, Deirdre has been the glue that bonds our operations, sales, marketing and finance teams to deliver products to our customers," Cook said. "Deirdre deeply understands Apple's unique culture and that people join Apple to do the best work of their lives. She is a superb leader and I'm thrilled she will be bringing her experience and talent to this critical role."
She's played a vital role in every Apple hardware product launch over the past 20 years, the company said.
More of What's Trending on TheStreet:
- Chipotle CEO Should Be Canned for Not Apologizing to Sickened Customers in Virginia, Analyst Says
- O.J. Simpson's 4 Biggest Business Achievements
- Best Buy's Geek Squad Is a Mess According to Customer Reviews, Opening the Door for Amazon's Entry
- Sears' Kenmore Products on Amazon Is Hurting Home Depot, Jim Cramer Explains
- Former Apple Exec: 'It's Sad to See Apple Slipping to the Position of Follower'
- 5 Celebrities That Have Lost Big in Real Estate Like Golden State Warriors Star Steph Curry