In short: this comprehensive tutorial shows you how to install Ubuntu Desktop on a Raspberry Pi 4 device.
The revolutionary Raspberry Pi is the most popular single board computer. It has its own Debian based operating system called Raspbian.
There are several other operating systems available for Raspberry Pi, but almost all of them are lightweight. This suited the small factor and low-end hardware of the Pi devices.
That changes with the introduction of the Raspberry Pi 4B which displays 8GB of RAM and supports 4K display. The goal is to use Raspberry Pi as an ordinary desktop computer and it succeeds in doing so to a greater extent.
Before Model 4B, you could install Ubuntu server on Raspberry Pi but the desktop version was not available. However, Ubuntu Now Provides Official Desktop Image For Pi 4 Models.
In this tutorial, I will show the steps to install Ubuntu desktop on Raspberry Pi 4.
First, a quick overview of the prerequisites.
Prerequisites to run Ubuntu on Raspberry Pi 4
Here is what you need:
- A Linux or Windows system with an active Internet connection.
- Raspberry Pi Imager : The official Raspberry open source tool that allows you to get the distribution image on your SD card.
- Micro SD card: Consider using at least 16GB storage for your card, although a 32GB version is recommended.
- A USB-based Micro SD card reader (if your computer does not have a card reader).
- The essential accessories of the Raspberry Pi 4 such as an HDMI compatible screen, Micro HDMI to Standard HDMI Cable (A / M), Power supply (official adapter recommended), wired / wireless USB keyboard and mouse / touchpad.
It is recommended that you read the Pi requirements in detail beforehand.
Now, without further ado, let me quickly walk you through the preparation of the image for the SD card.
Preparing the Ubuntu Desktop Image for Raspberry Pi
Raspberry Pi provides GUI application to write ISO image to SD card. This tool can also automatically download compatible operating systems like Ubuntu, Raspbian, etc..

You can download this tool for Ubuntu, Windows and macOS from the official site:
On Ubuntu and other Linux distributions, you can also install it with Snap:
sudo snap install rpi-imager
Once installed, run the imaging tool. When you see the screen below, select “CHOOSE OS”:

Under “Operating System”, select “Other General Purpose Operating System”:

Now select “Ubuntu”:

Then select “Ubuntu Desktop 21.04 (RPI 4/400)” as shown below:

Insert the micro SD card into your card reader and wait for it to mount. Select “CHOOSE STORAGE” under “Storage”:

You should only see your micro SD card storage and you will instantly recognize it based on its size. Here I used a 32gb card:

Now click on “WRITE”:

I assume you have backed up the contents of the SD card. If this is a new card, you can simply continue:

Since this is a sudo privilege, you must enter your password. If you run sudo rpi-imager
from a terminal, this would not appear:

If your SD card is a little old, it will take a while. But if it’s a recent one with high speeds, it won’t take long:

I also wouldn’t recommend skipping the check. Make sure the image writing was successful:

Once it is complete, you will get the following confirmation:

Now safely remove the SD card from your system.
Use the micro SD card with Ubuntu on Raspberry Pi
Half the battle is won. Unlike the usual installation of Ubuntu, you haven’t created a live environment. Ubuntu is already installed on the SD card and is almost ready to use. Let’s see what’s left here.
Step 1: Insert the SD card into Pi
For new users, it can sometimes be a bit confusing to know where this map slot is! Do not worry. It is located under the table on the left side. Here is an inverted view with a card inserted:

Continue to slowly slide the card in this orientation into the slot on the bottom of the card, gently until it does not go any further. This means that it has just fitted in perfectly. There will be no click sound.

You may notice that two small pins fit into the slot (pictured above) when you place it inside, but that’s okay. Once inserted, the card would appear to protrude a bit. This is what it should look like:

Step 2: Configure the Raspberry Pi
I don’t need to go into details here, I guess.
Make sure the power cable connector, micro HDMI cable connector, keyboard and mouse connectors (wired / non-wired) are properly connected to the Pi board in the correct ports.
Make sure the display and power outlet are also properly connected before proceeding and turning on the power outlet. I would not recommend plugging the adapter into a live electrical outlet. To look for electric arc.
Once you have followed the two steps above, you can turn on the Raspberry Pi device.
Step 3: Running Ubuntu Desktop for the First Time on Raspberry Pi
Once you’ve turned on the Raspberry Pi, you’ll be prompted to do some basic setup the first time you run it. Just follow the on-screen instructions.
Select your language, keyboard layout, connect to WiFi, etc.
You will be prompted to select the time zone:

And then create the user and password:

This will set up a few things and it may take a while.
-
Finish installing Ubuntu -
Finish installing Ubuntu
It may take a while after that your system will restart and you will end up on the Ubuntu login screen:

You can start enjoying Ubuntu Desktop on Raspberry Pi now.

Conclusion
I noticed a temporary anomaly: A blinking red border on the left side of my screen during installation. This flicker (also of different colors) was also noticeable on random parts of the screen. But it disappeared after reboot and first boot.
It was a must for Ubuntu to start supporting popular ARM devices like Raspberry Pi and I’m happy to see it running on a Raspberry Pi.
Hope you find this tutorial useful. If you have any questions or suggestions let me know in the comments.