The singer plays a holiday camp entertainer in a feature-length episode for the detective drama series, which stars Martin Shaw as the title character.
For her appearance in the show, set in 1969, she plays Megan, a worker at the Blue Bird holiday camp.
Producer Matthew Bird said: "Pixie is very excited about joining the cast and we are delighted that she is making her TV acting debut in Inspector George Gently - we know she will bring something very special to the role."
Written by Jess Williams, this feature-length episode takes Gently and Bacchus to a family holiday camp to investigate staff and holidaymakers when the body of one of the entertainers is washed up nearby. The colourful inmates of the holiday camp, from the flamboyant owner and his sister, to the chalet girls, performers, lifeguards and guests, throw the investigation sideways as Gently and Bacchus uncover a story of jealousy, ambition and the dark underbelly of the permissive society.
Pixie Lott said: "I love the fact that Inspector George Gently is a period drama set in the Sixties. It is great to be filming in the North East, and playing a role that gives me a real feel for the period."
During today's filming, when asked what she thought about Saltburn, her response was simply, "Wet, sandy and cold," - hardly surprising when the series kicks off with a dead body washed up on the beach and you're it!
