Infobox last updated on: May 31, 2009.

Lilia Osterloh (born April 7, 1978 in Columbus, Ohio) is a tennis player from the United States, who started a professional career in August 1997. She reached her highest individual ranking in the WTA Tour in April 23, 2001, when she became World No. 41. Osterloh was eliminated in the quarterfinals of the women's tournament at the 1999 Pan American Games in Winnipeg, Canada, after losing to eventual gold medalist Maria Vento-Kabchi from Venezuela.