Baseball was a sport from Earth, played with a baseball and a baseball bat. An alternate, and presumably British, name for the sport was rounders — at least according to Izzy Sinclair. (COMIC: Wormwood)
The Sixth Doctor and Frobisher attempted to use the TARDIS to sneak into the Dodgers' baseball stadium in 20th century New York City without paying, in order to pick up Peri Brown. The Doctor got the coordinates wrong, and the TARDIS materialised in the middle of the baseball field instead. (COMIC: Time Bomb)
Jerome Weismuller, a CIA agent working in Wales in 1959, wore a baseball cap and jacket with the logo of the New York Yankees. (TV: Delta and the Bannermen)
The Seventh Doctor once proclaimed himself fond of baseball. He once watched Babe Ruth play in a 1926 game. (PROSE: Illegal Alien)
In 2008, the Blackwood Falls carnival was set up on the town's baseball field. (PROSE: Forever Autumn)