A series of highly near-infrared (NIR) transparent In2O3 thin films has been grown by ion-assisted deposition (IAD) at room temperature, and their optical and electrical properties characterized. The NIR transparency and the plasma edge can be engineered through control of the film deposition conditions. The as-deposited In2O3 thin films were employed as transparent electrodes for direct electro-optic (EO) characterization measurements via the Teng-Man technique. Using LiNbO3 as the standard, the relationship between the degree of electrode NIR transparency and Teng-Man EO measurement accuracy was evaluated. It is found that In2O3 electrodes can be tailored to be highly NIR transparent, thus providing more accurate Teng-Man EO coefficient quantification than ITO (tin-doped indium oxide). In addition, the EO coefficients of stilbazolium-based self-assembled superlattice (SAS) thin films were directly determined for the first time by the Teng-Man technique using an optimized In2O3 electrode. EO coefficients r33 of 42.2, 13.1, and 6.4 pm/V are obtained at 633, 1064, and 1310 nm, respectively.