May Ooi Yu Fen (Ooi Yu Fen, born 24 June 1976) is a retired Singaporean butterfly, freestyle and medley swimmer.

She competed in seven events at the 1992 Summer Olympics.

[1] She attended college at the University of Nevada, Reno from 1993 to 1997[2] and was a pre-med major.

After her swimming career she became a MMA fighter.

This biographical article related to a Singaporean swimmer is a stub.