FAQ: May I change my username?
May I change my WordPress username that I login with?
There is not a way to change your username that you login with. Your “Nickname” can be changed which is what is displayed publicly when you add posts or comment on posts. If you would like to change your “Nickname” you can do so by going to the Dashboard screen and clicking on “Users” on the left menu and then “Your Profile” and edit your Nickname and click “Update Profile” at the bottom of the screen.