Two different room-temperature liquid systems were investigated, both of which conduct a DC electrical current without decomposition or net chemical transformation. DC electrical conductivity is possible in both cases because of the presence of two different oxidation states of a redox-active species. One system is a 1 : 1 molar mixture of n-butylferrocene (BuFc) and its cation bis(trifluoromethane)sulfonimide salt, [BuFc⁺][NTf₂⁻], while the other is a 1 : 1 molar mixture of TEMPO and its cation bis(trifluoromethane)sulfonimide salt, [TEMPO⁺][NTf₂⁻]. The TEMPO–[TEMPO⁺][NTf₂⁻] system is notable in that it is an electrically conducting liquid in which the conductivity originates from an organic molecule in two different oxidation states, with no metals present. Single-crystal X-ray diffraction of [TEMPO⁺][NTf₂⁻] revealed a complex structure with structurally different cation–anion interactions for cis- and trans [NTf₂⁻] conformers. The electron transfer self-exchange rate constant for BuFc/BuFc⁺ in CD₃CN was determined by ¹H NMR spectroscopy to be 5.4 × 10⁶ M⁻¹ s⁻¹. The rate constant allowed calculation of an estimated electrical conductivity of 7.6 × 10⁻⁵ Ω⁻¹ cm⁻¹ for BuFc–[BuFc⁺][NTf₂⁻], twice the measured value of 3.8 × 10⁻⁵ Ω⁻¹ cm⁻¹. Similarly, a previously reported self-exchange rate constant for TEMPO/TEMPO⁺ in CH₃CN led to an estimated conductivity of 1.3 × 10⁻⁴ Ω⁻¹ cm⁻¹ for TEMPO–[TEMPO⁺][NTf₂⁻], a factor of about 3 higher than the measured value of 4.3 × 10⁻⁵ Ω⁻¹ cm⁻¹.