I'm trying to create a custom icon theme to make my install of QGIS a bit nicer, but I can't find where the icons are stored. All I've found is the QGIS logo in /usr/share/qgis/images/icons.
They are being packed into the application during the compilation phase.
You can find them at the source unpacked:
QGis 2.12 and up supports (?) themes. I suspect you want to create your own theme based on the default pack. You can find more info at :
I'm afraid you won't find qgis icon set in image format file within your installation. To see and change the icons, you need access to the source code and then compile it yourself.
All qgis source code is in github:
Icons are in the images folder:
Information on how to compile QGIS source code can be found here: