James Sloan Baumer (January 29, 1931 – July 8, 1996) was an American professional baseball player, scout, and front office executive.

A right-handed-hitting infielder born in Tulsa, Oklahoma, Baumer was a graduate of Broken Arrow Senior High.

The day of his last MLB game, April 27, 1961, the Reds acquired second baseman Don Blasingame in a trade with the San Francisco Giants.

Baumer's most successful transaction during his three-year tenure as GM was his acquisition of first baseman Cecil Cooper from the Boston Red Sox following the 1976 season.

However, the Brewers struggled on the field, and after their eighth straight losing season in Milwaukee in 1977, Baumer was fired and replaced by Harry Dalton.