Win App Update claims that the Microsoft operating system passed the landmark figure on November 20, but notes that not all apps are available globally.
There are currently 20,610 applications on the Windows Store, almost 90% of which are free to download.
Canada presently has access to more Windows 8 apps than any other country with 14,000 accessible in the territory. The US came in second on 12,675 and the UK in third with 11,000.
By comparison, Apple's desktop App Store took four months to hit the 10,000 apps milestone, but surpassed the 100 million mark in less than a year.
Windows 8 was released for PCs and tablet computers last month.
> Read Digital Spy's review of Windows 8