Juan Castillo Brayas (born January 25, 1962) is a former professional baseball player.

He played all or part of four seasons in Major League Baseball from 1986 until 1989, all for the Milwaukee Brewers.

[1] Castillo was originally signed as an amateur free agent in 1979 by the Brewers.

After playing in the Cleveland Indians organization in 1990, he returned to the Brewers to start the 1991 season.

He finished the year with the Rieleros de Aguascalientes of the Mexican League, and continued to play on and off in Mexico until 1998.