Frederick Helsher Rath Jr. (born January 5, 1973) is an American former Major League Baseball pitcher who played for the Colorado Rockies in 1998.

Rath played his first professional season with their rookie league Elizabethton Twins in 1995 where he posted a 1.35 era in 33.1 innings, recording 50 strikeouts and 12 saves to lead the team.

In 1996, Rath made the Midwest League All-Star Team while playing for the Fort Wayne Wizards with 14 saves and a 1.51 era in 41.2 innings.

Rath earned a promotion to the Fort Myers Miracle after the all-star break and recorded another 4 saves in 29 innings of work.

Just after the start of the season, Rath was placed on waivers and was selected by the Colorado Rockies and made his major league debut on July 29, 1998.