Robert Francis Klaus (born December 27, 1937), is a former right-handed Major League Baseball infielder who played from 1964 to 1965 for the Cincinnati Reds and New York Mets.

Originally signed as an amateur free agent by the Cincinnati Redlegs in 1959, Klaus made his big league debut on April 21, 1964, against Jimmy Wynn and the rest of the Houston Colt .45s as a pinch hitter for pitcher Jim O'Toole.

In his big league career, he played in 215 total games, collecting 123 hits in 590 at-bats for a .208 batting average.

Although his big league career ended after the 1965 season, he still stuck around in pro baseball for a while, and was part of some notable transactions.

Finally, on March 28, 1969, he was traded by the Padres with Ron Davis to the Pittsburgh Pirates for Tommie Sisk and Chris Cannizzaro.