A locking spacer assembly for filling a void between adjacent components in a turbine engine. In at least one embodiment, the locking spacer assembly may be configured to be inserted between adjacent turbine blades in a disc groove in a turbine blade stage assembly. The locking spacer assembly may be formed from radially inward and outward supports coupled together with a locking device. The inward and outward supports establish the desired spacing between adjacent blade supports. The locking device may include components that prevent the locking device from accidentally loosening during use.