We present new XMM-Newton observations of the supernova remnant (SNR) N 120 in the Large Magellanic Cloud, and numerical simulations on the evolution of this SNR which we compare with the X-ray observations. The SNR N 120, together with several H II regions, forms a large nebular complex (also called N 120) whose shape resembles a semicircular ring. From the XMM-Newton data, we generate images and spectra of this remnant in the energy band between 0.2 and 2.0 keV. The images show that the X-ray emission is brighter toward the east (i.e., toward the rim of the large nebular complex). The EPIC/MOS1 and MOS2 data reveal a thermal spectrum in soft X-rays. Two-dimensional axisymmetric numerical simulations with the Yguazú-a code were carried out assuming that the remnant is expanding into an inhomogeneous interstellar medium with an exponential density gradient and showing that thermal conduction effects are negligible. Simulated X-ray emission maps were obtained from the numerical simulations in order to compare them with the observations. We find good agreement between the XMM-Newton data, previous optical kinematic data, and the numerical simulations; the simulations reproduce the observed X-ray luminosity and surface brightness distribution. We have also detected more extended diffuse X-ray emission that is possibly due to the N 120 large H II complex or superbubble.