How do I find out my root MySQL password?

You can reset the root password by running the server with --skip-grant-tables and logging in without a password by running the following as root (or with sudo):

# service mysql stop
# mysqld_safe --skip-grant-tables &
$ mysql -u root

mysql> use mysql;
mysql> update user set authentication_string=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

# service mysql stop
# service mysql start
$ mysql -u root -p

Now you should be able to login as root with your new password.

It is also possible to find the query that reset the password in /home/$USER/.mysql_history or /root/.mysql_history of the user who reset the password, but the above will always work.

Note: prior to MySQL 5.7 the column was called password instead of authentication_string. Replace the line above with

mysql> update user set password=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';

I realize that this is an old thread, but I thought I'd update it with my results.

Alex, it sounds like you installed MySQL server via the meta-package 'mysql-server'. This installs the latest package by reference (in my case, mysql-server-5.5). I, like you, was not prompted for a MySQL password upon setup as I had expected. I suppose there are two answers:

Solution #1: install MySQL by it's full name:

$ sudo apt-get install mysql-server-5.5

Or

Solution #2: reconfigure the package...

$ sudo dpkg-reconfigure mysql-server-5.5

You must specific the full package name. Using the meta-package 'mysql-server' did not have the desired result for me. I hope this helps someone :)

Reference: https://help.ubuntu.com/12.04/serverguide/mysql.html