Complex index of refraction values of RP-1 liquid rocket fuel are reported at laser wavelengths of 0.193 μm (ArF excimer), 0.5145 μm (argon-ion), 0.532 μm (Nd-YAG, frequency doubled), 1.064 μm (Nd-YAG), and 10.5915 μm (CO2). The imaginary part of the index of refraction (k) was determined by the traditional transmission method. The real part (nr) is determined by reflectance measurements, critical angle, Mueller matrix, and Michelson interferometer techniques. Reflectance measurements are used to obtain nr at a wavelength of 0.193 μm. Critical angle method is used to determine nr at 0.5145 μm and 0.532 μm. The real part of the refractive index is obtained from Snell's law by measuring the critical angle. The real part of the refractive index at 1.064 μm is derived based on elements of the Mueller matrix. Specular measurements were performed using a TMA scatterometer to obtain the Mueller matrix. A Michelson interferometer is used to determine nr at 10.5915 μm.