How do you put on armor in minecraft?

Answer 1

Click on your piece of armor, and place it into the corresponding armor slot to the left of your character in the top left of your inventory. Another, easier method, is to hold down Shift, and Left click the armor in your inventory.

Answer 2

Open the inventory and you will see a picture of you and the body slots around you that the armor goes in, drag the armor to the respective areas.