Mariana Simionescu (born 27 November 1956) is a retired tennis player from Romania.

Her best Grand Slam performance was reaching the fourth round at Wimbledon in 1977.

Simionescu married Björn Borg on 24 July 1980, but the marriage ended in 1984.

[1] She never remarried, but lived with former F1 racer Jean-Louis Schlesser for a few years, with whom she has a son (Anthony).

This biographical article relating to Romanian tennis is a stub.