The nuclear magnetic moment of the 143Ce ground state (T1/2= 33.0 h, Iπ= 3/2-) has been measured with the technique of nuclear magnetic resonance on oriented nuclei (NMR-ON) at low temperature. A sample (143CeFe) was prepared by implanting into an Fe foil nuclei of mass number 143, which were separated from fission products with an on-line isotope separator. The NMR-ON spectra were obtained by detecting specific β and γ rays, and the resonance frequency was thereby determined to be 84.3(1) MHz. Using the reported value of the hyperfine magnetic field at other Ce nuclei in Fe, the nuclear magnetic moment of the 143Ce ground state was determined to be μ=0.43(1) μN. This value is discussed based on a systematics of the magnetic moments of other N= 85 nuclei.