Provided is a pre-equalization optical transmitter capable of generating a pre-equalized RZ-type optical signal with a simple and low-cost structure. Further provided is a pre-equalization optical fiber transmission system in which dispersion is appropriately managed by using the pre-equalization optical transmitter. The pre-equalization optical transmitter includes: an RZ conversion circuit (11) for generating an RZ-type input data sequence based on an NRZ-type input data sequence (D (t)) and a clock (p (t)) that is twice the speed of the NRZ-type input data sequence; a digital filter (12) for generating pre-equalized data by a convolution operation between the RZ-type input data sequence and a desired transfer function corresponding to the wavelength dispersion of an optical fiber transmission path; D/A converters (13a, 13b) for performing D/A conversion on the pre-equalized data to output analog pre-equalized data; and a vector modulator (15) for modulating light from a laser light source (14) based on the analog pre-equalized data to output an RZ-type optical signal.