I Know This Much Is True

Mark Ruffalo

Dominick Birdsey / Thomas Birdsey· 6 ep

Melissa Leo

Concettina Ipolita Tempesta 'Ma' Birdsey· 6 ep

Rosie O'Donnell

Lisa Sheffer· 6 ep

Archie Panjabi

Dr. Patel· 6 ep

Kathryn Hahn

Dessa Constantine· 6 ep

John Procaccino

Ray Birdsey· 6 ep

Rob Huebel

Leo· 6 ep

Michael Greyeyes

Ralph Drinkwater· 6 ep

Gabe Fazio

Shawn Tudesco / Dominick and Thomas Acting Double· 6 ep

Rocco Masihi

Young Thomas Birdsey· 4 ep

Donnie Masihi

Young Dominick Birdsey· 4 ep

Laura Esterman

Ruth Hood· 3 ep

Imogen Poots

Joy Hanks· 3 ep

Bruce Greenwood

Dr. Hume· 2 ep

Marcello Fonte

Domenico Onofrio Tempesta· 2 ep

Annie Fitzgerald

Miss Hanker· 2 ep

Joseph Ragno

Henrey Rood· 2 ep

Acahkos Johnson

Penny Ann Drinkwater· 2 ep

Jaiden Klein

Marie Sexton· 2 ep

Charlie Reina

Channy· 2 ep

Violet Adams

Bunny Borsa· 2 ep

Oliver Patnode

Otero· 2 ep

Matt Helm

Young Leo· 2 ep

Derek Goh

17-19 Year Old Dominick & Thomas Acting Double· 2 ep

Agatha Nowicki

Angie Constantine· 2 ep

Irene Muscara

Prosperina Tucci· 2 ep

Adrienne R. Williams

Mrs. Birdsall· 2 ep

Tatanka Means

Nabby Drinkwater· 2 ep

Philip Ettinger

Early Adulthood Dominick Birdsey / Thomas Birdsey· 2 ep

Aisling Franciosi

Young Dessa Constantine· 2 ep

Juliette Lewis

Nedra Frank· 2 ep

Harris Yulin

Father Lavie· 1 ep

Sue Jean Kim

Dr. Yup· 1 ep

Michael Simon Hall

Stuart Feinstein· 1 ep

Gina Costigan

Mrs. O'Meara· 1 ep

Steven Cox

Boyfriend of Dr. Hume's Daughter· 1 ep

MorningStar Angeline

Nabby Drinkwater's Wife· 1 ep

Al Linea

Abruzzi· 1 ep

Richard Fitch

Mill Foreman· 1 ep

Amy Lynn Stewart

Merciful Mother· 1 ep

Guillermo Díaz

Sergeant Mercado· 1 ep

Marylouise Burke

Librarian· 1 ep

Brian Goodman

Al· 1 ep

Sandra Berrios

Social Worker at Hatch· 1 ep

Laura Silverman

Kristin· 1 ep

Christine Parks

Humanities Department Chair· 1 ep

Morgan Sullivan

Office Buddy· 1 ep

Jake Robards

Landlubbers (voice)· 1 ep

Michael Genet

Thomas' Surgeon· 1 ep

María Gonzalez

Ma's Oncology Nurse· 1 ep

A.C. Peterson

Gene Diogenes· 1 ep

Christopher J. Hanke

Thad· 1 ep

James Quattrochi

Bus Driver· 1 ep

Rachel B. Joyce

Jeanette· 1 ep

Paul Coleman

Support Group Counselor· 1 ep

Brandon J. Dirden

Kyle's Dad· 1 ep

Katt Masterson

Doreen· 1 ep

Jason Furlani

Larry Penn· 1 ep

Kate Grimes

English Professor· 1 ep

Chelsea Sheets

Brunette· 1 ep

Felix Solis

Nurse· 1 ep

Joe Grifasi

Steve Falice· 1 ep

Raymond Neil Hernandez

Omar· 1 ep

Simone Coppo

Vincenzo Tempesta· 1 ep

Sean Cullen

Dr. Yates· 1 ep

Federico Dordei

Nunzio Tucci· 1 ep

Shannon Plumb

Charlotte· 1 ep

Zaria Degenhardt

11 Year Old Concettina· 1 ep

Mark A. Gamma

Mourner Mark· 1 ep

Wayne J. Miller

Mourner Wayne· 1 ep

Thomas Gionet-Lavigne

Ray's Orderly· 1 ep

Alexander Hacker

Templeton· 1 ep

Robert Mladinich

Paddy Wagon Officer· 1 ep

Destry Allyn Spielberg

Dr. Hume's Daughter· 1 ep

Roberta Riganò

Ignazia Tempesta· 1 ep

Tim Ruddy

Robocop· 1 ep

Ethan Crystal

Thin Sailor· 1 ep

James Pravasilis

Third Guard· 1 ep

Michael Armand DeMatteo

Fatso· 1 ep