Major League Baseball’s first regular season games in Europe were played in London in June 2019, featuring the Yankees and Red Sox.
The Cubs and Cardinals were supposed to play there on June 13 and 14, 2020, but those games were cancelled due to the COVID-19 pandemic. (I had planned to go to those games.)
Now, this video interview with Sadiq Khan, the mayor of London, seems to indicate a return to London for MLB — next year (note the timestamp if you want to scroll in for the exact quote):
“Major League Baseball coming back to London next year,” the mayor says in that video clip.