Gyromagnetic Faraday rotation offers a new method to probe limits on properties of simple spin systems such as the possible magnetic moment of asymmetric dark matter or as a polarization monitor for polarized targets. Theoretical calculations predict the expected rotations of linearly polarized light due to the magnetization of spin-1/2 particles are close to or beyond the limit of what can currently be measured experimentally (10−9 rad). So far, this effect has not been verified. Nuclear spin polarized 3He provides an ideal test system due to its simple structure and ability to achieve high nuclear spin polarization via spin-exchange optical pumping (SEOP). To maximize the expected signal from 3He, a SEOP system is built with a modern narrowband pumping laser and a 3He target designed to use with a multipass cavity. Additionally, a sensitive triple modulation apparatus for polarimetry is utilized and further developed to detect Faraday rotations on the order of nanoradians. This works presents the results of the measurement of the magnetic Faraday effect.