What is the setting of John Wick?

Williamsburg, Brooklyn, New York City, New York, USA (When John attempts to kill Viggo in a parking lot nr. Peter Luger’s.)

Is John Wick based on a true story?

The story is loosely inspired by an incident in Texas involving former Navy SEAL Marcus Luttrell, who wrote Lone Survivor, about his fireteam’s ordeal during Operation Red Wings in Afghanistan in 2005. Luttrell was given a yellow labrador puppy, whom he named DASY, after the members of his fireteam.