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 singles ranking on the WTA Tour on April 23, 2001, when she became World No. 41. Her career high doubles ranking on the WTA tour is No. 77, which she reached on August 23, 1999.