A wire lock includes a body having an opening therethrough, a locking member disposed at least partially within the opening, and a biasing device. The biasing device urges the locking member into a configuration wherein a wire passing through the opening is restrained in at least one direction, and may operate in either tension or compression. The locking member may include one or more locking elements that are compressed about the wire through engagement with a wedge-shaped locking section of the body, with the biasing member urging the locking member against the locking section. In other embodiments, the locking member is a locking pin riding on an inclined surface of an elongate slot extending across the body, with the biasing member urging the locking pin against one end of the slot, and the wire pinched between the pin and a body surface opposite the inclined surface.