In the chromium browser shipped with Fedora, there is not such option.
In the package shipped with Ubuntu, there is such option.
However, as far as I can see, this option is not a Chromium option, but on Ubuntu it is provided by the bash script that actually launches Chromium. It is a wrapper around another option.
If you look at the Ubuntu’s (and Debian) package, for instance the source package, there is a script called
--temp-profile option is provided here.
while [ $# -gt 0 ]; do
case "$1" in
if [ $want_temp_profile -eq 1 ] ; then
$LIBDIR/$APPNAME $CHROMIUM_FLAGS "$@"
rm -rf $TEMP_PROFILE
--temp-profile option is a wrapper for the Chromium’s
--user-data-dir= actual option, that is documented in the man page, plus an