We report a direct measurement of the 7s ²S_1/2 → 7p ²P_3/2 electric dipole transition frequency in ²²⁶Ra⁺. With a single laser-cooled radium ion we determine the transition frequency to be 785722.11(3) GHz by directly driving the transition with frequency-doubled light and measuring the frequency of the undoubled light with an iodine reference. This measurement addresses a discrepancy of five combined standard deviations between previously reported values.