|Birth Name||Lyle O'Donohoe|
|Date of Birth||September 25, 1994|
|Place of Birth||Flesherton, Ontario, Canada|
Lyle Lettau (born O'Donohoe) is a Canadian actor, best known for portraying Tristan Milligan, being introduced in the second part of Season 11 of Degrassi. He is known for portraying, "The Brain" in the most recent episodes of the TV show, Arthur. He is currently a senior at Flesherton's Grey Highlands Secondary School. His inspirations are Marilyn Monroe, Andy Warhol, and Lady Gaga.
- Lyle is a Libra.
- He ships Eclare (Eli and Clare).
- He had wanted to be on Degrassi since he was ten years old.
- His favorite Degrassi characters are Darcy, Paige, and Manny.
- He hates trying on clothes, and says wardrobe fittings are the only part of the job he doesn't like.
- He is a huge fan of Lady Gaga.
- Lyle ships Camaya (Cam and Maya).
- He originally auditioned for Mo before landing the part of Tristan.
- His favorite band is No Doubt.
- He is a big fan of Quentin Tarantino.
- He doesn't like The Big Bang Theory.
- Lyle loves American Horror Story.
- He has 3 dogs.
- He does not like Ashley Kerwin and rolls his eyes whenever she is on-screen.
- Lyle is best friends with Alex Steele, like his character Tristan Milligan is best friends with her character Tori Santamaria.
- He dyed his hair blonde.
- On June 12th, 2013, Lyle revealed on Tumblr that he has decided to go by Lyle Lettau rather than O'Donohoe in honor of his grandmother, and that he would be credited as such in the 13th season of Degrassi and onwards.
- He is a huge fan of Lana Del Rey, and frequently quotes her songs on Twitter and Tumblr.
- For playing the part of Tristan, Lyle had to wear a body suit up until I Want It That Way (2).
- He moved to Los Angeles in November 2013.
- Lyle is a huge fan of Buffy the Vampire Slayer and cites Sarah Michelle Gellar as one of his heroes.