Conductive organic and composite films represent the critical component of many areas of technology. This study demonstrates that highly conductive coatings can be made by layer-by-layer (LBL) assembly of single-walled carbon nanotubes (SWNTs). These films reveal electrical conductivities of 102 to ∼103 S/m at room temperature without doping with nanotube loading as low as ∼10%. This is indicative of efficient utilization of SWNT in percolation pathways. Low SWNT loading also makes the coatings quite transparent with transmission as high as 97% for visible light. Thicker delaminated LBL films displayed conductivities of 4.15 × 104 S/m. The free-standing films were highly flexible and possessed 160 MPa of tensile strength, which makes them the strongest organic conductor. The high strength and conductivities are attributed to the unique homogeneity of the LBL assembled composites, which opens the way to future optimization of electrical, mechanical, and optical properties and to fit the needs of specific a...