- Dwayne Johnson as Raymond "Ray" Gaines, a chief rescue helicopter pilot with the Los Angeles Fire Department
- Carla Gugino as Emma Gaines, Ray's estranged wife
- Alexandra Daddario as Blake Gaines, Ray and Emma's daughter
- Ioan Gruffudd as Daniel Riddick, Emma's boyfriend and owner of a civil engineering firm
- Archie Panjabi as Serena Johnson, a news reporter
- Paul Giamatti as Dr. Lawrence Hayes, a Caltech seismologist
- Hugo Johnstone-Burt as Ben Taylor, Ollie's older brother, an English engineer and Blake's love interest
- Art Parkinson as Ollie Taylor, Ben's younger brother
- Will Yun Lee as Dr. Kim Park, a Caltech seismologist, and Lawrence's research partner and closest friend
- Kylie Minogue as Susan Riddick, Daniel's sister
- Alec Utgoff as Alexi, Lawrence's student
- Todd Williams as Marcus Crowlings, a fellow Los Angeles Fire Department rescue helicopter winch operator
- Marissa Neitling as Phoebe, Lawrence's student,
- Matt Gerald as Harrison Rhodes, a fellow Los Angeles Fire Department rescue helicopter co pilot
- Colton Haynes as Joby O'Leary, a Los Angeles Fire Department rescue helicopter winchman
- Arabella Morton as Mallory Gaines, Ray and Emma's other daughter and Blake's sister, who drowned in a rafting accident. (flashback).
Other cast members include:
- Morgan Griffin as Natalie
- Breanne Hill as Larissa, a waitress
- Julian Shaw as Stoner
- John Reynolds as Daniel's driver
- Hugh Francis as Daniel's assistant
- Brad McMurry as Riddick Building Security Guard
- Ben McIvor as Dylan, Serena's cameraman
- Joey Vieira as man in parking garage.
