The Cupertino-based firm's grip on the sector has grown by 13.3% since the launch of the new iPad in March, helped on by a steep drop in shipments of Android tablets.
Apple's gain came partly at the expense of Amazon's Kindle Fire, which fell from a 16.8% share in the fourth quarter of 2011 to 4% in the first quarter of this year, the latest data from IDC suggests.
"Apple reasserted its dominance in the market this quarter, driving huge shipment totals at a time when all but a few Android vendors saw their numbers drop precipitously after posting big gains during the holiday buying season," said IDC research director Tom Mainelli.
"Apple's move to position the iPad as an all-purpose tablet, instead of just a content consumption device, is resonating with consumers as well as educational and commercial buyers. And its decision to keep a lower-priced iPad 2 in the market after it launched the new iPad in March seems to be paying off as well."
Amazon's slump allowed Samsung to emerge as the closest contender to Apple, followed by Lenovo, Barnes & Noble and Microsoft.
IDC predicts that Android tablets will claw back market share from Apple in the coming months, with Samsung and Lenovo products "gaining traction" and Amazon planning to expand its Kindle range.