Solution 1:

For Xcode 4 or later:

  • Open a project
  • Select Project Navigator
  • Highlight project name
  • Single click on project name

Screenshot of the Project Navigator

For Xcode 3:

  • Open a project > Menu > Project > Rename ...

Solution 2:

There is no need to change the name of the project in order to change the display name of the application (which is what you see on the home screen of the iOS device, in iTunes, etc.). Simply change the "Bundle display name" in your info.plist from the default "${PRODUCT_NAME}" to whatever you want it to be. The name of your project is invisible to users, they only see the "Bundle display name."