Calamaria muelleri, also known commonly as Mueller's reed snake or Müller's reed snake, is a species of snake in the subfamily Calamariinae of the family, Colubridae. The species is native to Indonesia.
The specific name, muelleri, is in honor of Swiss herpetologist Fritz Müller.
Females of Calamaria muelleri are longer than males. Females have a total length (tail included) of , but males have a total length of only .
In Boulenger's original description of this species the total length of the holotype is printed as being "1900 millim." (6 feet 3 inches). This is obviously a typographical error, and probably should have been .
Calamaria muelleri is endemic to the island of Sulawesi (Celebes) in Indonesia.
The preferred natural habitat of Calamaria muelleri is forest.
Calamaria muelleri is terrestrial, foraging in the leaf litter of the forest.
Calamaria muelleri is oviparous.