Yes. For the most part, GRUB and Systemd-boot should be able to coexist inside the same system. This means that you can convert a machine that uses GRUB over to Systemd-boot.
It is important to keep in mind that installing Systemd-boot will differ depending on your Linux distro. In most cases, however, this will involve loading your OS in UEFI mode and running su && bootctl install.