A slew of Apple product releases came as the California company's stock rose on the back of record high net profit and revenue in the quarter ending June 25.
Lion is the latest version of the Macintosh computer operating system and boasts more than 250 added features including handling multi-touch controls.
Sales of Macintosh computers dramatically outpaced the overall market in the recently-ended quarter and Lion is expected to further ramp up interest in Apple products.
Lion will be pre-installed on new Macintosh computers and is available for download as an update from the Mac App Store for $30.
"Lion is the best version of OS X yet, and we're thrilled that users around the world can download it starting today," said Apple senior vice president of Worldwide Product Marketing Philip Schiller.
Updated MacBook Air laptops feature speedier Intel processors, backlit keyboards, and quicker data ports.
MacBook Air models range in price from $999 to $1,599 depending on processor speeds, memory and other features.
Apple also introduced a Thunderbolt Display that serves as a docking station and a high-quality desktop screen for a Mac notebook computer. Thunderbolt Display will be priced at $999 when it hits the market some time in the coming two months, according to Apple.