The video player has been in the works since 2008, but its roll-out suffered numerous delays caused by infrastructure upgrades and personnel changes, AllThingsD reports.
Video start-up Kaltura and Google joined forces with the online encyclopaedia to launch the service with around 15,000 videos, some of which are beta tests, with others in the older Ogg Theora format.
"Wikipedia has more than half a billion unique monthly visitors, so any new feature that is deployed needs to be really sustainable and foolproof," said Kaltura president Michal Tsur.
Uploading video content to Wikipedia will not be as simple as embedding a YouTube video online, as all footage must first go through Wikimedia Commons to ensure it does not infringe upon the site's terms and conditions or violate licensing laws.
Mobile format support and full video editing features will be added to the service at a later date.