Quarry was created in 1971 while author Max Allan Collins was a student at the Iowa Writer's Workshop, and later appeared in four novels between 1976 and 1977, with a 5th (and supposedly final) book appearing in 1987. However, in 2006 publisher Charles Ardai of Hard Case Crime appealed to Collins to write a another Quarry novel, which eventually lead to a new series of books featuring the character. As of 2016, HCC has published 7 additional books about the hit man.

The Quan Thang flashback in the season one finale consisted primarily of a single take lasting 7 minutes and 30 seconds.

Quarry's real name is never revealed in the book series upon which the show is based. The TV show's producers christened him Mac Conway in homage to his author/creator Max Allan Collins, (ie MAC).

On May 31, 2017, creator Michael D. Fuller officially announced that the show was cancelled by Cinemax.

A handful of local antique car owners were used to stage all the other cars during the shoot in Memphis. The local owners antique cars were used in some shots.

In the first teaser, the song was "You Don't Miss Your Water" by Otis Redding. However, HBO/Cinemax only had the rights for the song for a period of time. Therefore, when the promo was aired/uploaded again (before the series finale of Banshee), the song was changed to "Brighter Day" by Noel McKoy.

Quarry is depicted as a strong swimmer in various scenes, prompting an unsavory heavy to refer to him sarcastically as "Spitz," a reference to Olympic swimming legend Mark Spitz who was breaking records at the 1972 Summer Olympics (Munich), a time frame in which this plot unfolds.

Director Greg Yaitanes was revealing a picture diary from the set while shooting. He would post pictures from the set on Twitter, stating the day of shooting. Some of the pictures were pics of the episode scripts that revealed the titles one by one.

The song in the first trailer that was released for the show is "You Don't Miss Your Water" by Otis Redding. The first episode's title is "You Don't Miss Your Water".

Jason Yaitanes, director Greg Yaitanes' brother, is designing the main title sequence.

Was cancelled after just one season on May 31st 2017

Peter Mullan (The Broker) & Josh Randall (Detective Tommy Olsen) also worked together on Ozark (2017) as Jacob Snell & Bruce Liddell respectively.

Logan Marshall Green's first listed role is in a Law & Order: SVU episode. In the same episode, Ann Dowd also appears.

Peter Mullan (The Broker) & Lindsay Ayliffe (Mr Stout) also worked together on Ozark (2017) as Jacob Snell & Harry respectively.

Quarry received an eight-episode series order in February 2015 and filming began on March 30, 2015.

In episode 2 the waitress brings coffee but it is water in the pot

The restaurant used in some scenes, for its original decor, is an actual, working, family-owned, Italian, restaurant named 'Coletta's', and is located in Memphis, TN.

The scenes that took place in the fictional strip club, 'The Boobie Trap', were filmed in a pizza place called 'Victor's Pizza' located in Holly Springs, Mississippi.

In episode 1.08, there's a boat with the word "Horla" written on it. "Horla" was the original name of episode 1.05, before it was changed to "Coffee Blues".