|Born||27 October 1907|
|World Champion||Argentine Champion|
Isaías Pléci (also Isaias Pleci) (27 October 1907 - 27 December 1979) was an Argentine chess master.
Pléci was the Argentine Champion in 1929 to 1930. He won at Buenos Aires 1928 (ARG-ch 7 Mayor) and lost a match for the title to Roberto Grau (0 : 4). later, he won in 1929 (ARG-ch 8) and won a match against Grau (5 : 3) in 1930. He won a match against Virgilio Fenoglio (6 : 4) in 1931. He lost a match to Jacobo Bolbochán (3 : 6) in 1931. He won ARG-ch 11 Mayor in 1932 and lost a match to Bolbochán (1,5 : 5,5) in 1933. He took second, behind Grau, in ARG-ch 13 Mayor in 1934. He took second, behind Bolbochán, in ARG-ch 14 Mayor in 1935. He tied for 3rd-5th in ARG-ch 15 Mayor in 1936 (Carlos Guimard won). He took 3rd in ARG-ch 16 Mayor in 1937 (Bolbochán won). In 1953, he tied for tenth in ARG-ch; Oscar Panno won.
In other tournaments, Pléci tied for first with Bolbochán and Fenoglio at Buenos Aires 1930. He took second, behind Victor Soultanbeieff, at Liege 1930 (Quadrangular) and took twelfth at Liege 1930 (Savielly Tartakower won). In 1934/35, he took second, behind Luis Piazzini, in Buenos Aires (the 5th South American Chess Championship). In 1936, he won, ahead of Aaron Schwartzman, in the 3rd Torneo Internacional de Mar del Plata (the 6th Campeonato Sudamericano).
Pléci represented Argentina in three Chess Olympiads.
He won the individual gold medal at Buenos Aires 1939 and the bronze medal at Stockholm 1937. In the 1939 Olympiad, he played the following brilliancy against Lucius Endzelins of Latvia. Alekhine wrote in 107 Great Chess Battles of Pleci's 11. Rd8!!: "A truly brilliant conception which makes this a pearl from the Buenos Aires tournament.":
He was awarded the International Master (IM) title in 1965.