Edmar John Mednis (Latvian: Edmārs Džons Mednis; March 22, 1937 – February 13, 2002) was an American chess player and writer of Latvian origin. He was awarded the title of Grandmaster by FIDE in 1980.

Mednis' family were refugees in 1944 during World War II. As displaced persons, Edmar and his two sisters, with parents Edvin and Marita Mednis, were permitted to emigrate to the United States in 1950. Mednis was trained as a chemical engineer, then worked as a stockbroker, but became best known as a chess author. He wrote 26 chess books, including Practical Rook Endings (1982) and Strategic Chess: Mastering the Closed Game (1993), and hundreds of chess articles. He and Robert Byrne annotated many games for Chess Informant.

Mednis finished second in the 1955 World Junior Championship behind Boris Spassky (the two drew their game). He was the first player to beat Bobby Fischer in a U.S. Championship. He played on the 1962 US team at the 15th Chess Olympiad and finished equal third in the 1961–62 U.S. Championship. Tournament results included third at Houston 1974, equal fourth at New York City 1980, and equal first at Puerto Rico 1984. The Puerto Rico Chess Federation, rather than the United States Chess Federation, formally proposed him for the Grandmaster title. He played in the 1979 Interzonal tournament in Riga, his birthplace and finished 15th equal.

Mednis died of complications from pneumonia on February 13, 2002.