Louis Masterson (AKA: Kjell Hallbing), is a Norwegian author who between 1966-1985 wrote the hugely popular Morgan Kane series of western novels - a series of books about the fictitious Texas Ranger (later U.S. Marshal) Morgan Kane taking place in the 19th century. The 83 Morgan Kane books have so far sold more than 20 million copies worldwide. He has also written another nine-book series known as the Diablo- and Diablito books, also featuring Morgan Kane.

Earlier in his career, Masterson, used the pseudonyms Ward Cameron, Leo Manning, Lee Morgan and Colin Hawkins. His debut "Ubåt-kontakt" was released in 1961, written under his real name, Kjell Hallbing. The same year he released his first book set in the old West, "Portrett av en revolvermann" ("Portrait of a gunslinger").

In addition Louis Masterson was an eager weapon collector, resulting in his collection being one of the biggest privately owned weapon collections in Norway at the time of his death. He also owned a little house at Bolkesjø, where he wrote most of the books in the Morgan Kane series.

Other "heroes" Hallbing/Masterson wrote about, were Jesse Rawlins, Owen Metzgar and Clay Allison.

Before he started to write full-time in 1969, Hallbing worked as a bank employee.