Offseason
- November 30, 1964: Tim Cullen was drafted by the Senators from the Boston Red Sox in the 1964 first-year draft.
- December 1, 1964: Chuck Hinton was traded by the Senators to the Cleveland Indians for Woodie Held and Bob Chance.
- December 4, 1964: Claude Osteen, John Kennedy and $100,000 were traded by the Senators to the Los Angeles Dodgers for Frank Howard, Ken McMullen, Phil Ortega, Pete Richert and a player to be named later. The Dodgers completed the deal by sending Dick Nen to the Senators on December 15.
Read more about this topic: 1965 Washington Senators Season