The Springfield Isotopes are Springfield's only minor league baseball team.
The team plays at the Double-A level and is often shown as drastically underfunded and struggling in competition. Their home games are played at Duff Stadium as Duff Beer sponsors and co-manages the team, but they also play at the Springfield War Memorial Stadium and at the Isotope Stadium. The Isotopes name is most likely in reference to Springfield's nuclear power plant. Homer Simpson was the Isotopes mascot for a brief period, before taking over from the Capital City Goofball, before being fired. Players include Flash Bailor, Fishbone Walker, Smash Diggins, Bill McCloskey, Buck Mitchell and Babe Ruth IV.
The low quality of the team combined with its financial difficulties has prompted management to consider moving the team. Homer once learned that the there were plans to move the team to Albuquerque, and staged a hunger strike to prevent it. Springfield become aware of their plans to move the team due to Homer's efforts and their premature roll-out of food packaging with "Albuquerque Isotopes" written on them. Albuquerque decides to change the decision to move the team.
- Special – The Simpsons SU2C PSA (flag)
- Special – Join The Simpsons at the Daytona 500 (logo)
- – "The Simpsons Guy"
- Comic story – It's in the Cards
- Comic story – Children off the Cob