For years, teachers have requested to ability to use videos in Google Slides, without the need to host them on YouTube. Yesterday, Google finally made this possible!
Just add your video to Google Drive. Then Insert Video within your Slides presentation. You’ll see a new option for Google Drive.
If a person viewing your presentation doesn’t have permission to view a video embedded within it, they’ll be prompted to request access.
Note that while you can play Drive videos in Slides on the web and mobile, you can only insert them from the web application. For more details, visit the Help Center.
This feature should be rolling out to users within the next two weeks.