Read more: In this short video tutorial, learn how to tag someone on Instagram using the Instagram app on your Android device. You can tag someone or people on Instagram in several different ways. instagram tags How To Tag Someone on a Photo You are Sharing: When sharing a photo on Instagram, you can tag someone from the share screen. Tap on the photo and start typing the username of the person you want to tag. How to Tag Someone in a Photo You already Shared: Go to the photo and open it. Tap on the menu ibn the upper right side and select ‘Tag People’. You can also tag (mention) someone in a comment on any post that is public. Simply start typing the username preceded with the ‘@’ symbol.