Both shows will bow on Sunday, Jan. 9, along with the fourth season premiere of David Duchovny's "Californication."
"Shameless" will air at 10 p.m., while "Californication" kicks off the evening at 9 p.m. and "Episodes" follows at 9:30.
For the premiere night, LeBlanc and "Episodes" co-stars Stephen Mangan and Tamsin Greig will host the evening.
Showtime will look to promote the night via the cable premiere of "The Twilight Saga: New Moon" on Saturday, Jan. 8, and a replay on Jan. 9 leading into "Californication."
John Wells and Paul Abbott are behind "Shameless," which stars Macy as the father of an unusual Chicago family. Emmy Rossum is his oldest daughter. John Wells Productions and Warner Bros. Television produce; Wells and Abbott are executive producers.
"Episodes," created and exec produced by David Crane and Jeffrey Klarik, centers on a British couple whose UK series is turned into a U.S. sitcom starring LeBlanc. Jimmy Mulville also executive produces; Hat Trick is the production company.