I Know What You Did Last Summer (2025): Full list of cast and characters explored

I Know What You Did Last Summer was released theatrically by Sony Pictures on July 18, 2025. The film follows Ava, Danica, Milo, Teddy, and Stevie—who are involved in a tragic accident on a Fourth of July night. A truck driver gets wounded when Teddy's careless actions cause it to swerve off a cliff. Instead of getting help, the group hides what happened with Grant, Teddy's powerful father. When Danica gets a strange note a year later that says, "I KNOW WHAT YOU DID LAST SUMMER," a new chapter of terror starts. 

A killer starts going after the group while dressed as a fisherman and holding a hook. As the killings happen, the friends realize that the killer knows their secret. They ask Julie James and Ray Bronson for help because they lived through the first killing spree. Stevie admits that she killed the man for being upset about the death of her boyfriend.

The main cast of the movie features Madelyn Cline, Chase Sui Wonders, Jonah Hauer-King, Tyriq Withers and more.

Main Cast of I Know What You Did Last Summer

1) Madelyn Cline as Danica Richards

One of the main characters in the movie is Danica Richards, played by Madelyn Cline. Danica is a young woman who is still dealing with the effects of a bad choice she made a year ago. The person she plays is smart, resourceful and struggling with guilt. The 1997-born Cline is best known for her role as Sarah Cameron in the hit Netflix show Outer Banks (2020–present). She has also made contributions as a model and been a part of Glass Onion: A Knives Out Mystery (2022).

2) Chase Sui Wonders as Ava Brucks

Chase Sui Wonders plays Ava Brucks, who is also in the doomed group. Ava is determined, very protective, and scared and angry at the same time. Born in 1996, Chase Sui Wonders has played a major role in HBO's Generation (2021) and the movie Bodies Bodies Bodies (2022). She was also in The Studio (2025), an Apple TV+ show. 

3) Jonah Hauer-King as Milo Griffin

Milo Griffin played by Jonah Hauer-King, is one of the friends who helped cover up the murder. Hauer-King was born in 1995 and is best known for his part as Prince Eric in Disney's The Little Mermaid (2023). He has also been in World on Fire (2019–2023) and Howards End (2017). 

4) Tyriq Withers as Teddy Spencer

Teddy Spencer, played by Tyriq Withers, was careless the night of the accident, which led to all the chaos that followed. Teddy has a lot of charm, but he also makes a lot of bad choices, and the movie is about how he learns those lessons. He was born in 1998 and got his start in acting with parts in Legacies (2019) and Tell Me Lies (2022). 

5) Sarah Pidgeon plays Stevie Ward

Sarah Pidgeon stars as Stevie Ward, whose guilt and trauma drive her to commit acts of violence. Stevie’s character is complex, filled with grief and rage over the past events. Pidgeon, born in the 1990s, is known for her role in The Wilds (2020–2022) and Tiny Beautiful Things (2023). 

Supporting Cast

• Freddie Prinze Jr. as Ray Bronson
• Billy Campbell as Grant Spencer
• Sarah Michelle Gellar as Helen Shivers
• Gabbriette as Tyler
• Jennifer Love Hewitt as Julie James
• Austin Nichols as Pastor Judah Gillespie
• Nick Farnell as Chief Roberts
• Joshua Orpin as Wyatt
• Georgia Flood as Hannah Decker
• Nick Hardcastle as Neal
• Simone Annan as Jill Spencer
• Isaiah Mustafa as Andrew
• Leah McKendrick as Newscaster
• Luke Van Os as Officer Johnson
• Brian Duffy as Groundskeeper
• Todd Giebenhain as Jason
• Brandy Norwood as Karla Wilson
• Dalia Rooni as Courtney

Crew Details

• Director: Jennifer Kaytin Robinson
• Writers: Jennifer Kaytin Robinson, Sam Lansky, Leah McKendrick
• Producers: Matt Gustafson, Neal H. Moritz, Karina Rahardja
• Executive Producers: Jennifer Kaytin Robinson, Jackie Shenoo
• Composer: Chanda Dancy
• Cinematographer: Elisha Christian
• Editor: Saira Haider

I Know What You Did Last Summer (2025) is running in theaters.