States in 18N have been populated in the neutron-adding (d,p) reaction on the short-lived 17N beam. Previously observed levels, found in this work at excitation energies of 0.12(1) MeV and 0.74(1) MeV, have been identified as those expected from a proton 0p1/2 hole coupled to the 19O 5/2 + ground state. A new state at 1.17(2) MeV is consistent with the coupling of the 1/2- proton-hole state to the excited 1/2+ state in 19O. Orbital angular momentum assignments and spectroscopic factors were determined from the measured angular distributions through a distorted wave Born approximation analysis. Systematics for the (0d5/21s1 /2)3 neutron configurations in the N=11 isotones, 17C, 18N, and 19O are discussed and comparisons to p-sd shell-model calculations are made.