丰富海（拉丁语：Mare Fecunditatis，又译丰饶海、丰海）是月球上一座直径909公里的月海，位于月球的东南部。

丰富海盆地形成于前酒海纪，月海周围的地质生成于酒海纪，而月海自身地质却属于晚雨海世，其地质层较危海或静海薄。丰富海盆地与酒海、静海和危海盆地相重叠。在西侧，该盆地通过一条弧形地堑与酒海盆地接壤；东侧是朗伦环形山。月海中央附近坐落着二座有趣的月坑-梅西耶陨石坑和梅西耶 A 陨坑"(Messier A)，成功湾则位于丰富海的东侧边沿。

不像其它许多的月海，丰富海中心没有质量瘤或高重力。1968年，美国五艘月球轨道飞船的多普勒测量仪在其它月海(如澄海或雨海)中心都探测到了质量瘤 ，后来的轨道飞行器，如月球勘探者和圣杯号飞船则高精度地绘制出了重力场图，从而揭开这一异常的形态。

Mare Fecunditatis (the "Sea of Fecundity" or "Sea of Fertility") is a lunar mare which is 840 km in diameter. The Fecunditatis basin formed in the Pre-Nectarian epoch, while the basin material surrounding the mare is of the Nectarian epoch. The mare material is of the Upper Imbrian epoch and is relatively thin compared to Mare Crisium or Mare Tranquillitatis. This basin is overlapped with the Nectaris, Tranquillitatis, and Crisium basins. Fecunditatis basin meets Nectaris basin along Fecunditatis' western edge, with the area along this zone faulted by arcuated grabens. On the eastern edge of Fecunditatis is the crater Langrenus. Near the center lie the interesting craters Messier and Messier A. It was here that the first automated sample return took place via the Luna 16 probe, in September of 1970. Sinus Successus lies along the eastern edge of the mare.