Popular video players like the Real Player, VideoLAN VLC, GOM Player and the Miro Vdieo Player can play Flash video* (FLV) without requiring any extra codecs. If you are on Windows, you can download the free K-Lite codec pack to play FLV files right inside your Windows Media Player while Mac users can install Perian to turn QuickTime into an FLV player.
FLV Player for your Flash Videos
Most people really don’t need a standalone FLV player because their existing media players can already handle the Flash Video format but in case you are still looking for one, check out FLVPlayer HD.
FLV Player HD is a simple Adobe AIR application with a minimalist interface that can playback FLV files in either full screen or the current player size. You can either use the Open button in the software to play FLV file or just drag-n-drop the video file onto the player window to start playback.
FLV Player HD is an AIR app so you may use it on a Mac, Windows or Linux machine.
[*] When you download a video from the Internet from sites like YouTube, chances are that your download manager will save that file using the FLV format. To learn more, see this detailed guide to Flash Videos.
Related: List of Audio & Video Media Players