Is it possible to hide or remove system preference panes?

The answer is Yes on both counts. That is, you can hide a preference pane or remove it altogether. See below for steps on doing each.

Hiding System Preference panes

To hide a System Preference pane:

1. Go to Apple > System Preferences…
2. With your mouse, go to View > Customize…
3. This will reveal a checkbox at the bottom-right of each pane (see image below)

4. Untick the checkbox of any pane you want to hide
5. Click on the Done button at top-left of the window

Note: You can also use the above steps to reveal any previously hidden panes by ticking the checkbox at Step 4.

Removing System Preference panes

You can only remove 3rd party preference panes (i.e. ones which are not natively part of macOS). To do this:

1. Right-click on the preference pane in question
2. Select the Remove “name“ Preference Pane option (in the example image below the user is selecting to remove the Java preference pane)

Login items

In case you're just wanting to hide an item upon logging in, or want to stop it loading on startup, you can also hide or remove items from your login items. To do this:

1. Go to Apple > System Preferences…
2. Click on Users & Groups
3. Make sure your user account is selected (it should be by default)
4. Click on the Login Items button
5. Now you will see a list of applications etc that automatically open when you log in
6. You can either:
   • Hide an item by ticking the checkbox on the left of it, or
   • Remove an item by selecting its name and then clicking on the minus - button below the list.

In System Preferences, choose View → Customize… and uncheck the items you wish to hide.