To change your Roblox username login to your account and go to the settings section. In a browser this is represented by the gear icon in the upper-right corner.

Gamertag, username, display name; a Roblox player has multiple names, each having a purpose. Thankfully, usernames and display names chosen years ago can be changed.

Steps for altering your avatar’s appearance in every Roblox experience, from adding and removing items to changing your skin ...

Roblox allows all users to change their Roblox account's display name in the account settings without spending a dime. Here's how to do it.