在Xcode 3.2中，只需要在Groups & Files面板中选择Project条目，然后选择菜单项Project→Rename…

如果您需要在iPhone主屏幕上更改应用程序的名称，则需要在Target配置中进行，而不是在项目配置中进行。

Expand the Targets group in Xcode, and then single-click the item under that. It should share the name of your project, which is also the default name of the application that gets generated. Press Command + I to bring up the Info window, and then navigate to the Build tag. Set the Configuration drop-down to read All Configurations. Look for a setting called Product Name under the Packaging heading. Change that value to the name you want for your compiled applications and, in the immortal words of Bugs Bunny: Voilà! Do a clean and a build. Your application will take on the new name.

下面的链接适用于Xcode 6，特别是当你在尝试重命名项目后出现错误时。基本上，你只需要为你的应用构建一个新方案。

https://stackoverflow.com/a/27572164/4114835

在新版本的Xcode (Xcode 5也是)中，要更改项目名称，请遵循以下简单(尽可能详细)的步骤:

注意:在这个例子中，我将把一个假设的“样本”名称改为“测试”名称。

Click twice slowly on the project root in the project navigator and then it becomes editable. Rename the project. After pressing Enter the assistant will suggest you to automatically change all project-name-related entries and will allow you to de-select some of them, if you want. Press 'RENAME' and Xcode will do the rest. In the meanwhile Xcode may ask you about the option of making a snapshot of the project (it is very recommendable to do so). In addition to renaming the project, you may want to rename the scheme so that it matches your new project name. Repeat similar steps like 1 and 2, and press OK. That's it.

另一个场景…

前面的解释与更改项目名称有关，但您可能只需要更改主屏幕应用程序图标下方的显示名称。以下是步骤:

在“支持文件”组中找到信息。Plist(或相关)文件 找到“Bundle display name”键并将值更改为新名称。 从模拟器或任何其他测试设备中删除“旧”应用程序。 再次清理并重新构建应用程序。 就是这样。现在你将在主屏幕上看到新的应用程序名称。

使用目标→构建设置→产品名称。

在Xcode 3.2中，只需要在Groups & Files面板中选择Project条目，然后选择菜单项Project→Rename…