Mary Elizabeth Hill (born November 8, 1985) is a former freestyle swimmer from the United States, who won the gold medal in the women's 400-metre freestyle event at the 2003 Pan American Games. A native of Atlanta, Georgia, she also won gold in the 800-metre free relay at the 2005 Summer Universiade, and finished fifth in the 200-metre freestyle and seventh in the 200-metre butterfly. In 2005 Hill also took seventh in the 200-metre butterfly and eighth in the 200-metre freestyle at the U.S. World Championship Trials.