Crystals of Na0.37Tb0.63F2.26 solid solution with a fluorite structure have been grown from melt by the Bridgman technique. The measured values of the Verdet constant are V = 0.35 ± 0.02 and 0.105 ± 0.01 arcmin/(Oe cm) for λ = 633 and 1060 nm, respectively. The dispersion of the Verdet constant is studied in the range of 380–1060 nm. The Na0.37Tb0.63F2.26 crystal is somewhat inferior to the previously studied noncubic fluoride crystals containing Tb3+ ions yields by V(λ) and is close to KTb3F10 crystal in totality of properties.