Both animated series will welcome a lengthy list of performers in autumn.
The Simpsons' 26th season will feature the voices of The Newsroom's Jane Fonda, Spider-Man's Willem Dafoe and Parks and Recreation's Nick Offerman.
Comedians Sarah Silverman and Jeffrey Ross, as well as Frasier's David Hyde Pierce will also guest star in the Fox series.
Meanwhile Seth Macfarlane's Family Guy will welcome the guest voices of Liam Neeson, Julie Bowen of Modern Family and Allison Janney of Mom.
Aside from an A-List line-up of actors, both series will also take part in a crossover episode.
The crossover episode - entitled The Simpsons Guy - is set to air on Fox, September 28.