Where is the power off button in Ubuntu 18.04 LTS ?

Solution 1:

If you click on the top right corner, it will show you a drop-down menu.

In that place, the power button is placed.

on login screen
in desktop session

It will open the menu with Cancel, Restart and Power Off:

Solution 2:

I currently don't have 18.04 installed, but if you can't find it you can always use the terminal and type the command:

sudo shutdown -h 0

This is how I typically shutdown my laptop.

Solution 3:

Sign In with Unity

To get the familiar interface to Ubuntu 16.04 LTS in Ubuntu 18.04 LTS you need to sign in using the Unity interface. Do this right on the Sign In screen:

Ubuntu 18 five desktops.jpg

click the "gear" to select the Unity Desktop Environment (DE).

Familiar look and feel

Now you will see the familiar "gear" on the top right of your screen where you can select "Lock Screen", "Log Out", "Suspend" and "Shutdown". If you press the power button you'll get your regular selector:

Ubuntu Power Button

This video also shows how to activate the lock screen option which is disabled for some users.

Also of interest is some users are not getting a chance to select an action because system shuts down immediately: How to make Ubuntu 18.04 LTS ask for action when I press ACPI Power button/key on VirtualBox (now immediately shutdowns)?