Extremly popular, with both carriers and retailers in Australia reporting "excellent" sales and "a lot of consumer interest" the M8 has also been labelled "The best smartphone in the world today" by several leading reviewers.
The phone launched in late March, so Q2 will represent the handset's first full quarter of sales.
This HTC One (M8) sales figure comes from a recent Digitimes report.
Channel sales of between 3 million and 5 million units might not seem terribly impressive compared to the numbers put up by HTC's top rivals. Samsung, for example, shipped 10 million Galaxy S4 smartphones in just one month last year. Meanwhile, Apple sold 9 million iPhones in one weekend in 2013.
But as HTC Australia General Manager Ben Hodgson said recently "HTC knows it can't beat giants like Apple and Samsung, and it isn't trying to beat them".
HTC president Jason Mackenzie said "The beauty for HTC and for our customers is we're not trying to be Toyota or GM and build these things for super mass production," Mackenzie said. "Our objective is not to sell the most phones, but to build the best phones and build a strong, loyal base."