Enabling SAGA in QGIS?

SAGA and the other Processing modules are configured under Processing -> Options and Configuration -> Providers.

From QGIS 2.0 onwards, SAGA should come with the QGIS standalone installer, so no need to install and configure it manually. I still use the 32bit version, maybe there are some bugs in the 64bit installation routines.

It might help to search the installation protocol postinstall.log for error messages.

If you used the OSGEO4W setup, all installations should go to C:\OSGEO4W or C:\OSGEO4W64; including SAGA and GRASS.

Try this: in the Processing -> Options -> Providers look for SAGA (2.1) and check Enable Saga 2.0.8 compatibility.

Worked for me on Ubuntu and Win8

I had the same problem and solved it by reinstalling QGIS 3.4.1, 3.0.1 ltr, SAGA 2.3.2 and 2.122 ltr all together from OSGeo4W shell.