Ubuntu – How to customize the context menu in Nautilus

You can do it with nautilus-actions. Launch nautilus-actions-config-tool and go to Edit > Preferences > uncheck "Create a root Nautilus Actions menu" and bottom of the first tab. -- This affects all actions.

Also, in the left panel the entries (actions) can be grouped as sub-menus. Create your actions (New action'), then create a 'New menu' with right-click or under 'File' for each action category, and then drag&drop your actions of that category on it.

Which gives this:

Update 2021-04-23

For the latest Ubuntu 20.04 LTS (focal fossa) the below actions are not needed, the package filemanager-actions is located in universe pocket. See fresh answer.

Update 2018-05-31

Daniel Marynicz has created PPA for Ubuntu 18.04 LTS with Nautilus, Caja and Nemo-enabled packages. You can install them as usual:

sudo add-apt-repository ppa:daniel-marynicz/filemanager-actions

sudo apt-get install filemanager-actions-nautilus-extension # Nautilus
sudo apt-get install filemanager-actions-caja-extension # Caja
sudo apt-get install filemanager-actions-nemo-extension # Nemo

sudo apt-get install filemanager-actions* # simply all filemanagers

After installation you can launch fma-config-tool.

Initial consideration of the problem:

Modern version of Nautilus Actions (nautilus-actions package in trusty (14.04 LTS), xenial (16.04 LTS), artful (17.10)) are named as FileManager Actions (filemanager-actions package, it is not yet packaged in Debian and Ubuntu - see at repology.org).

If you do not want to compile packages by yourself - use links in the end of this answer.

So we can try to compile this package locally:

1. Install dependencies

    sudo apt-get install build-essential gnome-doc-utils intltool \
    libnautilus-extension-dev uuid-dev libxml2-dev libgtop2-dev rarian-compat
   

   Note: if you need to support all three file-managers you should install two additional packages before compilation with sudo apt-get install libnemo-extension-dev libcaja-extension-dev.

2. Download, extract, configure, make (otherwise, if you prefer the easy way: use the deb file from links at the end of answer)

    cd ~/Downloads
    wget https://download.gnome.org/sources/filemanager-actions/3.4/filemanager-actions-3.4.tar.xz
    tar -xf filemanager-actions-3.4.tar.xz
    cd filemanager-actions-3.4
    ./configure
    make -j5
   

3. Install package

   • Here standard way is to use

        sudo make install
     

     but this will not create deb-package (but you can remove fma with sudo make uninstall);

   • so using checkinstall is better:

        sudo apt-get install checkinstall
        sudo checkinstall make install
        sudo apt-get install ./filemanager-actions_3.4-1_amd64.deb
     

After installation you will get new executable named fma-config-tool, its window is named FileManager-Actions Configuration Tool and looks like:

Below is the link to compiled package:

• only Nautilus support - download filemanager-actions_3.4-1_amd64.deb-package.