Abstract: Ultra-low power single metallic single-wall-nano-tube (SWNT) interconnects for sub-threshold circuits are provided. According to some embodiments, an interconnect structure for use in electronic circuits can generally comprise a first substrate, a second substrate, and an interconnect. The first substrate can be spaced apart from the second substrate. The interconnect is preferably a single wall carbon nanotube (SWNT) interconnect. The SWNT interconnect can be disposed between the first and second substrates to electrically connect the substrates. The substrates can form parts of electrical components (e.g., a transistor, processor, memory, filters, etc.) operating in a subthreshold operational state. Other aspects, features, and embodiments are claimed and described.