Techniques for field-programmable gate array (FPGA) virtualization are described herein. In one or more implementations, an FPGA virtualization manager of a host device receives a request from a virtual machine for a device, such as for a compression engine. The FPGA virtualization manager identifies an FPGA program associated with the request and configured to program FPGAs of the host as the requested device. The FPGA virtualization manager also checks the FPGA program against security policies of the host to determine whether to allow the FPGA program to program the FPGAs. If the programming is allowed, the FPGA virtualization manager allocates at least a portion of the FPGAs to the requested device and loads the FPGA program to program the allocated portion of FPGAs. The FPGA virtualization manager generates a virtual device to furnish the functionality of the programmed device to the requesting virtual machine.