The title refers to a prized display of a giant squid fighting a whale at the American Museum of Natural History, which appears in the final shot of the film.
Shot in 23 days.
Bill Murray was set to star in the main role, but backed out in the last minute because he wanted to take a break after filming Broken Flowers (2005). He was later replaced by Jeff Daniels.
The agency which Bernard gets the rejection letter from is ICM (International Creative Management). This is the agency of Jeff Daniels, who plays Bernard, and also of Laura Linney.
Anna Paquin, who plays a love interest to Jeff Daniels in the Squid and the Whale, played his daughter in Fly Away Home (1996). Upon the release of the Squid and the Whale, Jeff Daniels said that this previous experience made the filming a bit awkward for both of them. His comment to one interviewer about how he and Paquin got through the filming of their intimate scenes was, "we tried not to think about...you know, geese."
Noah Baumbach originally wanted Wes Anderson to direct but Anderson convinced Baumbach to direct it himself, due to the film being very personal to Baumbach.
Jeff Daniels was scheduled to film The Five People You Meet In Heaven when The Squid and The Whale was set to start production. The beard Jeff Daniels has in The Five People You Meet In Heaven is there only because he felt his character in The Squid and the Whale would have had a beard.