Marien Michel Ngouabi (born 3 June 1980) is a Congolese former swimmer, who specialized in sprint freestyle events.

[1] Ngouabi represented the Republic of the Congo at the 2000 Summer Olympics, where he became the nation's flag bearer in the opening ceremony.

[3] He challenged six other swimmers in heat two, including 15-year-olds Ragi Edde of Lebanon and Dawood Youssef of Bahrain.

Ngouabi failed to advance into the semifinals, as he placed sixty-eighth overall in the prelims.

[4][5] Ngouabi currently runs a small-scale company named Rosewood in Brazzaville, specialized in wood processing and furniture manufacturing.