Best TV Shows Guide: Why I Know This Much Is True Still Matters
A TMDB-backed guide to I Know This Much Is True, including cast, release facts, genres and watch-provider notes.

I Know This Much Is True (2020) — an evergreen reference for this TV series: the essentials, the cast, where to watch and what to watch next. You don't just give up on the people you love.
Where to watch
TMDB's U.S. watch-provider data lists HBO Max Amazon Channel, HBO Max. Availability changes by country and date, so check your streaming app before watching.
Cast
Mark Ruffalo as Dominick Birdsey / Thomas Birdsey; Melissa Leo as Concettina Ipolita Tempesta 'Ma' Birdsey; Rosie O'Donnell as Lisa Sheffer; Archie Panjabi as Dr. Patel; Kathryn Hahn as Dessa Constantine; John Procaccino as Ray Birdsey; Rob Huebel as Leo; Michael Greyeyes as Ralph Drinkwater
About I Know This Much Is True
The parallel lives of identical twin brothers Dominick and Thomas Birdsey in an epic story of betrayal, sacrifice and forgiveness set against the backdrop of 20th century America.
More like I Know This Much Is True
- This Is Us
- Monsters: The Lyle and Erik Menendez Story
- Half Man
- Wu-Tang: An American Saga
- Red Shoe Diaries
- The House of the Spirits
- Parish
- Black Cake
Figures and availability come from public TMDB data and are provided as a sourced reference.
Frequently asked questions
Where can I watch I Know This Much Is True?
TMDB's U.S. watch-provider data lists HBO Max Amazon Channel, HBO Max. Availability changes by country and date, so check your streaming app before watching.
Who is in the cast of I Know This Much Is True?
Mark Ruffalo as Dominick Birdsey / Thomas Birdsey; Melissa Leo as Concettina Ipolita Tempesta 'Ma' Birdsey; Rosie O'Donnell as Lisa Sheffer; Archie Panjabi as Dr. Patel; Kathryn Hahn as Dessa Constantine; John Procaccino as Ray Birdsey; Rob Huebel as Leo; Michael Greyeyes as Ralph Drinkwater
Is this I Know This Much Is True guide official?
No. It uses TMDB data as a reference and is not endorsed or certified by TMDB.



