The new iPad Pro has the power and capabilities to replace a laptop computer, Apple said.
Cook called the device "the biggest news in iPad since the iPad."
The new tablet with a 12.9-inch display also includes a detachable keyboard and stylus.
The device features "desktop-class performance" and operates faster than 80 percent of portable PCs that shipped in the last 12 months, said Apple senior vice president Phil Schiller of the device.
The new iPad will be available in November starting at $799, with a keyboard option at $169.
"It is thin and light enough to work all day and be taken everywhere," Schiller said.
The iPad Pro includes a stylus called Apple Pencil -- despite comments from late Apple co-founder Steve Jobs that consumers did not want such an accessory.
Cook said he expects the new tablet to offer new possibilities for computing as the original iPad did.
"The iPad is the clearest expression of our vision of the future of personal computing," Cook said.
"In just five years, iPad has transformed the way we create, the way we learn and the way we work."
The new tablet has 10-hour battery life, and a "forcetouch" screen which responds to the amount of pressure applied.
Bob O'Donnell at the research firm Technalysis said on Twitter that the new iPad "sure looks a lot like a Windows 2-in-1 (computer)...in fact, kind of similar to @surface," referring to the Microsoft tablet computer.