Q. If I find a video on YouTube, can I use it in my paper? What about using clips?

Your question entails two different issues. To refer to the video in your paper (in writing only) is fine. Just be sure to give proper attribution and use the citation style your instructor requires.

Regarding clips or stills, you will want to ensure that there are no copyright restrictions. Sometimes things get posted on YouTube illegally, so look for a Creative Commons license or something to indicate it's in the public domain. If that information isn't on YouTube, search for the video independently.

When in doubt, contact the production company or creator directly to ask.

I've provided a link to an online resource that goes into more details about obtaining permissions.