Lauren Graham will be playing Gaby, Oscar's ex wife. Matthew Perry and Lauren Graham are very good friends and dated briefly in the past. She also appeared in Go On (2012), in which Matthew Perry starred too. Graham also had a guest spot on Studio 60 on the Sunset Strip in which Matthew Perry's character asks her out, and she accepts, albeit unwillingly.
Thomas Lennon appears on How I Met Your Mother (2005) as Claus, in which at one point during season 8, he watches a show very similar to _The Odd Couple (2015)_, but in German. He points out that one roommate is "neat" and the other is "very, very neat."
Oscar's apartment is the same set as used for Frasier's apartment in _Frasier_, although totally refurbished. Also of interest is the fact that at on point on _Frasier_, Martin (Frasier's dad) moves in and is living with Frasier which is somewhat like The Odd Couple (2015) but with the roles reversed.
Garry marshall, who is the creator of the original and served as consultant on this version also plays Oscars dad, died on july 19. On the wall in oscars apartment is a photo of oscar, felix and dad garry as tribute to him.