  We report the discovery of soft X-ray pulsations from the nearby millisecond
pulsar PSR J1231$-$1411 using NICER. The pulsed emission is characterized by a
broad and asymmetric main pulse and a much fainter secondary interpulse, with a
total pulsed count rate of 0.055 c s$^{-1}$ in the 0.35-1.5 keV band. We
analyzed Fermi LAT data to update the pulse timing model covering 10 years of
data and used that model to coherently combine NICER data over a year of
observations. Spectral modeling suggests that the flux is dominated by thermal
emission from a hot spot (or spots) on the neutron star surface. The phase
relationship between the X-ray pulse and the radio and $\gamma$ rays provides
insight into the geometry of the system.
