Frank Rufus "Flossie" Oberlin (March 29, 1876 – January 6, 1952) was a Major League Baseball pitcher for the Boston Americans and Washington Senators.

Oberlin pitched four games for the Americans that year, going 1-3, striking out 13 batters and having an ERA of just 3.18.

Oberlin pitched 12 games with the Americans the next year before his contract was sold to the Washington Senators in August.

He pitched 11 more games with the Senators, finishing his 1907 season with a total record of 3-11.

He finished the 1916 season with the NYSL's Scranton Miners before retiring at age 40.