1. Go to the youtube video you wish to embed
  2. Click the embed tab :
  3. Copy the generated iframe code e.g. :  
  4. <iframe width="853" height="480" src="https://www.youtube.com/embed/UuqrbZ6KIj4?rel=0&amp;controls=0&amp;showinfo=0" frameborder="0" allowfullscreen></iframe>
  5. Go to the Wordpress page you wish to add this video.
  6. Edit this page. Go to the editor section and click the Text tab like so :
  7. Now paste you embed code.
  8. Click the update or publish button and view your post you should now see a youtube video embedded.