The film stars Jenny Slate, Edie Falco, Abby Quinn, John Turturro, Jay Duplass and Finn Wittrock, and follows sisters in 1990s New York City who think their father is having an affair.

Returning from a rave one night and trying to do her homework Ali unlocks a file containing her father's love-notes to a mysterious woman named "C".

Dana decides to move back home to "support" Ali and help her find C however she continues her affair with Nate and acts irresponsibly, blowing off her obligations.

The sisters hit a dead end, but at a staged reading of their father's play they meet Carla, an actress, and believe she is the C of the letters.

Dana is upset but when she mentions it to Nate he blows her off laughing that monogamy doesn't exist and causing her to end the affair.

On May 15, 2016, it was reported that Jenny Slate would star in Landline, reuniting with Obvious Child director Gillian Robespierre and producer Elisabeth Holm, alongside Edie Falco, John Turturro, Jay Duplass, and newcomer Abby Quinn.

The website's critical consensus reads, "Landline's talented cast — and a fast-paced approach from director/co-writer Gillian Robespierre — help this charming multi-generational dramedy overcome a familiar storyline.