How do I stop YouTube autoplay in Google Chrome?

I went to chrome://settings/content and changed the settings to "Click to Play".

This only works with Flash Videos. YouTube now uses HTML5 Video. The only way to disable auto-play is through an extension like this. Auto-loading video can also be disabled through this extension.

There is no way you can do it without a plugin, sorry. You can look at the other answers here for suggested plugins.

Note the statement was true in 2014 when it was written. Someone down-voted it more than four years later without stating a reason. Technology changes quickly and obviously old answers might become obsolete, so please take that into consideration and add updates in comments when necessary (as far as I know, there is no working solution without plugin in 2020). Thanks.

https://chrome.google.com/webstore/detail/stop-youtube-html5-autopl/ajkibmginjljbmmpgnipfbcbmkcodaap

This plugin worked for me. I'm not a big fan of plugins but until I find a better way..

I used this plugin

https://chrome.google.com/webstore/detail/magic-actions-for-youtube/abjcfabbhafbcdfjoecdgepllmpfceif/related

It has a bundle of other options I want to have set other then just no autoplay.

Chrome will defer autoplay in background tabs in one of the next versions (46 most likely, to be released in late October). It is not yet in 45 (which is stable at the time of writing), but Canary (48) does not autoplay YouTube in background tabs when the browser is opened. I like it. However, if you pull one of the YouTube-Tabs to the foreground, the video will still start to play automatically.

Source: Blog post by François Beaufort (who also gives away the target version 46 in the comments)