Williams, according to the Hollywood Reporter, will play himself in an episode titled "New Year's Eve." Ed O'Neill's character Jay will meet Williams over a game of cards in Palm Springs, where the family is celebrating the new year.
Lane will reprise his role as the flamboyant Pepper Saltzman in the subsequent 14th episode of the season.
The Nov. 14 episode, which is entitled "Mistery Date," features a guest appearance by Tony winner Matthew Broderick and is described as such: "When Claire takes Manny and Luke along to Alex's academic decathlon for the weekend, Phil attempts to throw together a boys' night at the house, inviting a fellow Bulldog alum (guest star Matthew Broderick) he just met -- but their wires are definitely crossed. Meanwhile, the pressure is on for Alex at the decathlon, Manny and Luke bar mitzvah hop at the hotel trying to find a cute girl, and Cam and Mitch arrange for quite the surprise baby gift for Jay and Gloria."
"Modern Family" stars Ed O'Neill as Jay, Julie Bowen as Claire, Ty Burrell as Phil, Sofía Vergara as Gloria, Jesse Tyler Ferguson as Mitchell, Eric Stonestreet as Cameron, Sarah Hyland as Haley, Nolan Gould as Luke, Ariel Winter as Alex, Rico Rodriguez as Manny and Aubrey Anderson-Emmons as Lily.
For more information on "Modern Family," visit ABC.com/ModernFamily.