- November 16, 1979: Bruce Kison was signed as a free agent by the Angels.
- December 6, 1979: The Angels traded Willie Aikens and Rance Mulliniks to the Kansas City Royals, in exchange for Al Cowens, Todd Cruz, and a player to be named later.
- January 11, 1980: Kevin Romine was drafted by the Angels in the 3rd round of the 1980 Major League Baseball draft, but did not sign.
- March 30, 1980: Danny Boone was released by the Angels.
- April 1, 1980: The Angels received Craig Eaton from the Royals, completing the trade of December 6.