MKV is quite a popular video format as it is mainly used for storing and distributing high-resolution videos over the Internet. Here I'll share the top 3 MKV players for Mac, with which you can easily playback MKV files on Mac OS X (Sierra included) without any trouble. As a solution, you can install some plug-ins to boost QuickTime's native file support for the MKV file.
Unfortunately, the official Apple QuickTime player doesn't support the.mkv file by default.