Called the B+, the updated version uses less power than its predecessors and will cost about $35 (£20).
The B+ can also power more peripherals without the need for a dedicated power source and has more connectors to help link it to other devices.
The new model is released as the Pi faces increasing competition from other tiny computers.
The B+ is based on the same Broadcom chip as earlier versions and has the same 512Mb of memory but a variety of other changes have been made to the device.
The analogue and composite video connector has been ditched in favour of a four-pole connector and the SD card slot has been replaced with a micro-SD card unit.
Better power management on the B+ will mean it can keep four USB peripherals going without requiring mains power or an external hub.
"We've been blown away by the projects that have been made possible through the original B boards and, with its new features, the B+ has massive potential to push the boundaries and drive further innovation," said Pi co-creator Eben Upton in a statement.
The B+ will be available via online electronics stores such as Element 14.
The Pi now faces much more competition from devices such as the Beaglebone Black, the Hummingboard, the APC 8750, the Android MK802 mini PC, Banana Pi and the Matrix TBS2910.