Today I was trying to change my name displayed in Office 365 suite bar and when viewing the profile.
And as it often happens simple things lead to difficult solutions.
Let's first analyze how the suite bar works and where 'My profile' and 'My account' links lead.
Suite bar itself shows user's avatar and name. When you click on name you'll see a pane with links to 'My profile' and 'My account'.
'My profile' link leads to Delve, 'My account' to user's account page for the Office 365 tenant (https://portal.office.com/account/).
Both Delve and Office 365 User Profile contain User Name.
In Delve it is read only... OK, let's change it in Account Settings for Office 365.

  • Select Personal info in left nav
  • Click Edit in About section
  • Change First Name or Last Name and click Save
Cool... we changed the name. But both Delve and Suite still display the old one...
OK, let's return to Delve and click Update profile to switch to edit mode. So, the Contact information is read only but there is a help section 'Why can't I edit my contact information?':

Hmmm... How did we change user information in classic SharePoint? In User Profile Settings in Central Administration!
Let's try the same in SharePoint Online:
  • Navigate to SharePoint Admin (classic one, I didn't find the same functionality in New Admin Center)
  • Select User profiles in left nav
  • Select Manage user profiles in People section
  • Search for your profile
  • In context menu select Edit my profile
  • Change Name and First and Last Name
  • Click Save and close
Now let's return to Delve... and now it displays changed name! Cool!
But Suite bar still displays old one...
What did we forget?
Actually, we just need to look a bit deeper. All users in Office 365 are stored in Azure AD. And we haven't changed user's properties in Azure AD. So, let's do that.
  • Go to https://portal.azure.com
  • Select Azure Active Directory in left nav
  • Select Users and Groups -> All Users
  • Click on name of needed user in the list of users
  • Select Profile
  • Change Name, First Name and/or Last Name
  • Click Save
  • Clear browser data
No we're good and the correct name is displayed in Suite Bar.
So, here are the steps to change your name in Office 365/SharePoint Online:
  • Change it in Azure AD
  • Change it in Office 365 My account
  • Change it in SharePoint Admin user profiles
Hopefully, it will help you!
Have fun!