The short answer is yes. But there are some interesting issues. You want to be careful that you don't share a root partition, or a /boot partition, etc. Not that you can't mount the partitions of one OS from the other, but you don't want to use the same /etc, /boot, /lib, /usr/lib and probably a host of others because they contain configuration or kernel data.
But, you should be able to share a /home directory and possibly a /var directory.
pansophic