Jan Koch

Upon activation, this plugin uses the “automatic_updater_disabled” filter to prevent automatic updates from being installed. 
It does not offer configuration, not even an options page in WP Admin.
Simply install and activate the plugin to disable all automatic updates. Deactivate the plugin to re-enable all automatic updates.

Stop Automatic Updates

This plugin disables all automatic updates. No configuration needed.

Johan van der Wijk

This plugin disables all WordPress updates (core, plugins and themes). This can be useful if you have multiple environments such as a live and staging server and you don’t want your users to use the update functionality.
This plugin not only disables the update mechanism for the core, plugins and themes, but it also removes the update menu item from the left navigation menu in the admin dashboard.

Disable Updates for WordPress Core, Plugins and Themes

Disables the WordPress update checking and notification system for all core, plugin and theme updates.

Stop Automatic Updates vs Disable Updates for WordPress Core, Plugins and Themes