Abstract: Implantable biomedical device leads comprising liquid conductors. In an exemplary embodiment of a lead for use in a biomedical application of the present disclosure, the lead comprises a lead body having a distal end and a proximal end, the lead body defining a first interior lumen therethrough, and an electrically conductive composition positioned within the first interior lumen, the electrically conductive composition comprising a metal in a liquid state at or below about 98° F. In another embodiment, the electrically conductive composition is selected from the group consisting of gallium, a gallium-indium alloy, Galinstan, its/their alloys, and combinations thereof. In various embodiments, the metallic electrically conductive composition is used along with a second non-metallic electrically conductive composition such as a conductive polymer, an electrically conductive liquid, an electrically conductive gel, or combinations thereof.