Lars Kepler is the pseudonym of husband and wife team Alexandra Coelho Ahndoril (b. 1966) and Alexander Ahndoril (b. 1967), authors of the Joona Linna series. With six installments to date, the series has sold twelve million copies in 40 languages. The Ahndorils were both established writers before they adopted the pen name Lars Kepler, and have each published several acclaimed novels.

The Joona Linna series follows Joona Linna, Detective Superintendent at the police's National Operations Department, Saga Bauer, an Operational Superintendent at the Swedish Security Service, and Erik Maria Bark (in The Hypnotist and Stalker), a trained psychiatrist and psychotherapist specialised in psycho-traumatology and disaster psychiatry.

In the fall of 2015, Lars Kepler's sixth novel was published in Sweden, a stand-alone novel entitled Playground.