Billy Bob Thornton Lorne Malvo, Dr. Michael Actor Martin Freeman Lester Nygaard Actor Colin Hanks Gus Grimly Actor Allison Tolman Molly Solverson Actor Bob Odenkirk Bill Oswalt Guest Star Keith Carradine Lou Solverson Guest Star Keegan-Michael Key FBI Agent Pepper Guest Star Jordan Peele FBI Agent Budge Guest Star Joey King Greta Grimly Guest Star Susan Park Linda Park Guest Star Stephen Root Burt Canton Guest Star Helena Mattsson Jemma Stalone Guest Star Jennifer Copping Louise Weezy Canton Guest Star Noah Hawley Executive Producer Warren Littlefield Executive Producer Joel Coen Executive Producer Ethan Coen Executive Producer J. Geyer Kosinski Executive Producer