@thehans said in QOpenGLWidget::grabFrameBuffer() always ignores alpha channel?:

Unfortunately I'm on Ubuntu 18.04 which is still on 5.9.5.
Is there any chance of this fix being backported to earlier versions?

Qt 5.9 is now in "very strict" update mode, which means in only receives security fixes. It no longer receives bug fixes.

Your options are:

Download and use Qt 5.12 or newer from https://www.qt.io/download-open-source, OR Apply the patch to your copy of Qt 5.9 and build it from source.

I think the first option is easier.