Stanley Dean Royer (born August 31, 1967) is an American former third baseman/first baseman in Major League Baseball who played from 1991 through 1994 for the St. Louis Cardinals (1991–1994) and Boston Red Sox (1994).

Royer was selected by the Oakland Athletics in the 1988 draft out of Eastern Illinois University, from where he had earned an economics degree.

Before the 1991 season, he was sent by Oakland along with Félix José and a minor leaguer to the Cardinals in the same transaction that brought Willie McGee to the Athletics.

He also played in the Oakland, St. Louis and Boston minor league systems from 1988 to 1994, hitting .270 with 72 home runs and 417 RBI in 707 games.

Royer is President of Claris Advisors, an investment advising and wealth management firm based in St. Louis.