Dennys Reyes (born April 19, 1977 in Higuera de Zaragoza, Mexico) is a Major League Baseball relief pitcher for the St. Louis Cardinals. He has played for ten teams since his major league career began in 1997. Reyes throws left-handed and is considered a lefty specialist. He stands 6'3" and weighs 250 pounds. His nickname is 'The Big Sweat."

Reyes attended Ignacio Zaragoza High School in Mexico. He is married to Claudia and has two sons: Dennys Alejando and Kris de Jesus.

Reyes signed with the Los Angeles Dodgers as an undrafted free agent in 1993. He made his major league debut for the Dodgers on July 13, 1997 at age 20. He was the second youngest player in the league at the time, four days older than Atlanta Braves outfielder Andruw Jones. Reyes pitched with the Dodgers for parts of two seasons, compiling a record of 2-7 in 25 games, including eight starts. On July 4, 1998 Reyes was traded by the Dodgers along with Paul Konerko to the Cincinnati Reds for Jeff Shaw.