Open the downloaded CLion-*.dmg package and drag CLion to the Applications folder.
Open the Applications folder and launch the CLion installer.
If the security warning appears, agree to open the application:
When you install CLion manually, the update checking is performed automatically by default (every time the IDE is ready to update, you will see a message in the Status bar). To configure the update process, go to Preferences | Appearance and Behaviour | System Settings | Updates and select the update channel: Click Check now to perform the checking right away. In case there are available updates according to the chosen channel, you will see a dialog like the following:
Installation and update via Toolbox
Toolbox is a control panel that allows you to manage all JetBrains developer tools, including CLion, as well as your projects, from a single point of access. It enables you to maintain different versions of CLion, install updates and roll them back if needed. Toolbox remembers your JetBrains Account and uses it to automatically log in when you install and register new tools.
When the installation is complete, accept the JetBrains privacy policy and sign in to your JetBrains Account.
Now you can choose which version of CLion to install:
Toolbox shows the list of the installed versions:
In the Settings dialog, configure the way of updating CLion: Note that in case of using Toolbox, the update process cannot be configured from within the IDE. The Preferences | Appearance and Behaviour | System Settings | Updates dialog shows the following message:
After the installation or upgrade, you will be prompted to import, inherit, or create new settings for the IDE.
Required tools
CLion needs to be provided with C and C++ compilers and the make utility. These tools may be pre-installed on your system (check in Preferences | Build, Execution, Deployment | Toolchains, the compiler and make detection should perform successfully).
If your system does not have working installations of compilers and make, the simplest solution is to install Xcode command line developer tools.
Run the following command:
xcode-select --install
When prompted to install command line developer tools, click the Install button: You can also choose to install the full package of Xcode, though it is not necessary for CLion.
With Xcode command line tools, you get the Clang compiler installed by default. To check the compiler presence and its version, run clang --version.
Command line tools may not update automatically along with the system or Xcode update. This may cause error messages like invalid active developer path during project loading in CLion. To fix this, run the same xcode-select --install command, and the tools will be updated accordingly.
Note that you can use multiple compilers for the needs of your project, see Switching Compilers.
Configure toolchains
Now you need to configure the toolchain to work with, which means choosing the CMake executable, the make and C/C++ compilers location, and the debugger. Navigate to Preferences | Build, Execution, Deployment | Toolchains and edit the default toolchain, or click to add a new one.
CMake, make, and compilers
In the CMake field, specify the CMake binary that you want to use. You may stick to the bundled CMake, or use your custom CMake executable (see the minimum supported version in Software requirements).
The chosen CMake attempts to detect the compilers and make considering the packages installed on your system. If the detection succeeds, the fields Make, C Compiler, and C++ Compiler are filled automatically:
The detection of compilers and make fails if CMake cannot locate the appropriate tools (this may happen, for instance, if you installed them separately without the Xcode developer tools). In this case, you need to provide the actual paths manually.
Debugger
CLion for macOS comes with the bundled LLDB v 7.0.1 (the default debugger) and GDB v 8.0.1. You can also switch to a custom GDB (supported versions are 7.8.x-8.1.x). Select the debugger in Preferences | Build, Execution, Deployment | Toolchains:
Issues are possible when working with both bundled or custom GDB on macOS. To improve the behavior, enable the cidr.debugger.gdb.workaround.macOS.startupWithShell option in Registry (select Help | Find Action from the main menu and type Registry):
Note that enabling this option is not equivalent to setting set startup-with-shell off in your .gdbinit script.
Further steps
Now that you have CLion installed and configured, you may find the following articles useful for further steps of the development:
to add a new one. 
