The Glasgow-born Torchwood star, currently appearing in Clyde Auditorium panto Robinson Crusoe, has teamed up with his writer sister Carole to pen the fantasy novel Hollow Earth.
Glasgow's Kelvingrove Art Gallery and Museum and the Pencil Monument near Largs feature in the book, which is set on a Scottish island.
John and Carole started life in Mount Vernon but moved to America with their parents when they were children.
The new story is about a set of 12-year-old telepathic twins and is expected to be a big hit with fans of fantasies such as Harry Potter and Twilight. Matt and Emily Calder have powers which mean they can bring art to life and even become part of paintings.
But the story sees their abilities sought by villains who want to access the terrors of Hollow Earth, a place where all the demons, devils and evil creatures ever imagined lie trapped for eternity.
The action sees the twins flee from London with their Scottish mum to the fictional island of Auchinmurn, which the authors say is based on Great Cumbrae, and its smaller sister, Little Cumbrae.
Carole re-visited the area last summer and the name Auchinmurn is a tribute to her and John's Scottish gran Murn, their mother's mum.John said: "Both of us were really close to our Gran Butler – Murn, as we called her – and her sister, our Auntie Jeannie.
"When we lived in Scotland and our mum and dad went out on a Saturday night, Murn and Jeannie would watch us.
"Both of them loved to dance, play games, and we'd always have a good laugh together.
"The island where most of the novel takes place is a real place off the coast of Largs - but for the purpose of Hollow Earth we changed the island's geography and name.
"We named the island after Murn."
In the book, the twins' grandfather also visits Kelvingrove Art Gallery and Museum.
John and Carole said they were inspired by their own relationship to write the novel, the first in a series of four.
They said: "As siblings, we are often told we look a lot alike so when we were imagining our main characters we decided to make them twins.
"Lots of twins have a secret language with each other and that fitted in with our idea that the twins are telepathic."
Carole now works at Alverno College in Milwaukee, Wisconsin as a Professor of English and Director of Creative Studies in Writing.
She has also helped write John's two autobiographies.
John, 44, starred in West end musicals before finding fame playing Captain Jack in Doctor Who and spin-off Torchwood.
He's also been in Desperate Housewives and filmed BBC entertainment show Tonight's the Night in Glasgow, and he returned to the city this Christmas for his second panto with The Krankies.
n Hollow Earth by John and Carole E Barrowman is out on February 2.