Ellen Marie Estes (born October 13, 1978 in Portland, Oregon) is an American water polo player, who won the silver medal at the 2000 Summer Olympics. She also won a bronze medal at the2004 Summer Olympics. Estes scored three goals during the bronze medal game against Australia.
Estes played for Stanford University. She was a senior on the 2002 NCAA National Championship Team; was a two-time All-American; and broke a Stanford scoring record with 93 goals in her sophomore year. She graduated with an Engineering degree at Stanford, and interned for studied roller-coaster design as an intern with Disney.
In 2003, Estes was named the USA Water Polo Female Athlete of the Year.
- Olympic Games: Silver Medal (2000), Bronze Medal (2004)
- World Championships: Gold Medal (2003)
- Pan American Games: Second Place (1999)
- FINA World Cup: Second Place (2002)