The Antarctic stratospheric sudden warming (SSW) occurred on August 30, 2019, and was a vortex displacement minor warming event. We investigated variations in gravity waves (GWs) before and after this rare Antarctic SSW event using two satellite measurements (AIRS and CIPS) and reanalysis data (GEOS-5 FP). The observations showed that the GW activities decreased after the SSW onset, with a weakening of zonal wind. The decrease in GW activity coincided with a reversal of the zonal wind around September 8 in GEOS-5 FP. The temporal variation of GWs was similar to that of Arctic GWs during vertex displacement minor SSWs. The decline in GW activities was probably caused by wind filtering and polar night jet breaking. However, the GW activities over the Andes and the Antarctic peninsula decreased at the onset, although the westly wind was 40–60 ms^-1. This decrease could have been caused by wave saturation.