In a future where time travel exists but is illegal, the mafia uses technology to dispose of people by sending them 30 years into the past, where hitmen known as "loopers" execute them. These hitmen are well-compensated but understand that eventually, their future selves will be sent back for them to kill, effectively "closing the loop." This ensures that there is no future tie to the murder. Joe, a looper, lives a hedonistic lifestyle in 2044, saving his silver payoff in hopes of an eventual retirement. His life becomes complicated when his future self is sent back and manages to escape before Joe can kill him.

The plot thickens as Joe's future self is on a personal mission to alter his own destiny, driven by memories of a traumatic future. As Joe hunts for his older self in an attempt to fulfill his contract and close his loop, he encounters Sara, a single mother living on a remote farm with her son. She provides an unforeseen safe haven for him. Meanwhile, Joe's employers are after both versions of him, leading to a tense cat-and-mouse chase that makes Joe question his morality and his role within the time loop he's trapped in.