This paper presents an investigation of the generation of a plasma wave and a second‐harmonic electromagnetic wave in a collilsionless hot magnetoplasma by a Gaussian EM beam (pump wave) propagating perpendicular to a static magnetic field in the ordinary mode. Because of the Gaussian intensity distribution of the EM wave, the ponderomotive force becomes finite and the electrons become redistributed; the electron density gradient (so created) and the intensity gradient of the EM wave lead to the generation of a plasma wave at the pump‐wave frequency. The intensity of the magnetic field significantly affects the plasma‐wave generation. When the pump‐wave frequency is equal to the upper‐hybrid frequency, resonant excitation of the plasma wave occurs. The plasma wave interacting with the pump wave leads to the generation of a second‐harmonic electromagnetic wave. Moreover, as the pump wave propagates in the plasma, its self‐focusing occurs; consequently, the plasma‐wave and the second‐harmonic generation become drastically affected.