Leyson Séptimo Martinez (born July 7, 1985) is a Dominican former professional baseball pitcher.

[1] On June 13, 2011, Séptimo was claimed off waivers by the Chicago White Sox from the Arizona Diamondbacks and optioned to the Double-A Birmingham Barons.

[1] The next day, Séptimo made his Major League debut against the New York Yankees, pitching a perfect 9th inning while striking out Alex Rodriguez and Robinson Canó.

On October 29, it was confirmed that Septimo would be released from the Dragons along with Ricardo Nanita, Juan Jaime, Drew Naylor and Anderson Hernandez.

[9][10] On April 10, 2024, the Guerreros de Oaxaca of the Mexican League announced Septimo as their bullpen coach.