Waves play a major role in the ocean phenomena in the Gulf of Guinea (GoG). In order to reveal the spatial-temporal distribution characteristics and the propagation mechanism of waves from the South Atlantic Ocean to the GoG, 4 typical points located in mid-latitude of South Atlantic (14°30′W, 30°0′S), south of the GoG (10°30′W, 15°0′S), offshore of the GoG (0°0′, 0°0′) and near shore of the GoG (6°4′58.8″W, 4°3′36″S) are selected, and waves from Atlantic Ocean to GoG are simulated by using a two-layer-nesting wave numerical model SWAN (Simulating Waves Nearshore). The results show that the hybrid waves (waves hereafter) and the swells have strong relationship with local wind in Roaring Forties and at mid-latitude of South Atlantic Ocean, while there is no obvious correlation between waves and local winds in the GoG. Swells are generated in the South Atlantic Ocean and propagate into the GoG. 2D wave spectra at the four selected typical points are simulated. The spectral pattern and wave component structure indicate that the wave system in GoG is dominated by the S–SW swells generated from Roaring Forties and mid-latitude of South Atlantic, whether it is at maximum (2.2–2.8 m), medium (1.8–2.2 m) or minimum (1.2 m) significant wave height in the GoG during simulation period.