The smartphone is a slightly smaller version of its flagship smartphone the HTC One, with scaled-down specs to match.
The Mini still boasts a 720p 4.3-inch screen, along with a dual-core 1.4GHz Snapdragon processor, as well as 1GB of DDR2 RAM, 16GB of storage and an HTC UltraPixel camera.
The HTC One itself has a more impressive a 4.7-inch 1080p HD screen and a quad-core 1.7 GHz processor, and has been extremely warmly received both by users and the media in the months following its release.
HTC initially teased the announcement yesterday on Twitter, announcing that "we have a 'little' bit of news tomorrow."
"The HTC One mini embodies everything that makes the HTC One a success on a smaller but equally eye-catching scale," said Peter Chou, chief executive of HTC.
HTC said the phone will be available in some markets next month and then globally by September, although no word yet on Australian availability or pricing details.
The device will seemingly be a direct competitor to Samsung's Galaxy S4 Mini, which features a superior 1.66GHZ processor.
Apple has long been rumoured to be contemplating a 'mini' or scaled down version of its iPhone, much like it did with the iPad Mini, but so far nothing has eventuated.