Yes, KVM guests (e.g., Windows or OSX running in QEMU, using KVM) and Docker (e.g., Docker CE running containers) run fine all at the same time on the same Ubuntu instance.
Your question basically describes my workload. At this moment I'm running two Android emulators (using hardware virtualization acceleration, which is KVM on Linux), a Windows 10 QEMU guest, an OS X High Sierra QEMU guest, and Docker (installed via these instructions https://docs.docker.com/install/linux/docker-ce/ubuntu/) with their hello world example running, all at the same time on an Ubuntu 18.04 host.
The concise explanation why it works is that virtual machines (QEMU, etc) on Linux use a hypervisor (KVM in the case of QEMU, but Virtualbox and VMWare use different hypervisors) to use your computer's hardware resources, while Docker uses linux namespaces to simply use your currently running kernel's available hardware resources, but segregated from your main operating system.
In that way, KVM guests and Docker actually run using separate technologies and don't really even inter-relate to each other at the kernel level. This is in contrast to the case where you try to use different hypervisors (e.g., QEMU+KVM and VirtualBox) at the same time - that does not work as you can only run one type of hypervisor at a time (though you may run multiple VMs from each type of hypervisor).
There are great explanations of the technology details here: https://stackoverflow.com/questions/16047306/how-is-docker-different-from-a-virtual-machine