Clark principal David Bolen confirmed the hiring Tuesday in an e-mail to staff members at the school.
Ginter welcomed the opportunity to lead the baseball program at Clark.
"I'm excited to work with some of these kids and see what we can get done," he said.
Ginter, a former standout at Clark, enjoyed a successful career in the major leagues. He was drafted as the 22nd pick overall by the Chicago White Sox in 1999.
During his Major League career, Ginter compiled a 5-7 record, started 19 games, had one save and compiled a 5.43 earned run average.
Ginter, who hit three home runs in the majors, enjoyed his best season in 2004 with the Mets. Ginter went 1-3 and started 14 games. Ginter recorded 38 strikeouts.
Ginter played college baseball at Mississippi State and was a member of the U.S.A. World Cup baseball team in 1998. Ginter recorded a 5.40 ERA and collected one save in three appearances.
Ginter replaces longtime coach Larry Allison, who stepped down in August after guiding the Cardinals to their first-ever appearance in the state baseball tournament last June.