Nederkalix dialect (sometimes plainly Kalix dialect; endonym: kölismåle [kœɽɪsˈmɔːɽɛ]) is a traditional Norrland dialect of Swedish, spoken in the historical parishes (Swedish: socknar) of Nederkalix and Töre in modern-day Kalix Municipality in Norrbotten in Sweden. The traditional Nederkalix dialect, like the other Norrland dialects, is very divergent from Standard Swedish, containing both archaisms and innovations in the phonological and grammatical systems.

The Nederkalix dialect retains Old Norse diphthongs, Old Swedish light syllables, and many initial consonants lost in Standard Swedish. In terms of morphology, the dialect has also preserved plural agreement of verbs, as well as the dative case, which have been lost in Standard Swedish.

The Nederkalix dialect has innovated many diphthongs from older long vowels. It also displays features such as vowel balance, apocope (with preserved double-peak pitch accent), and vowel harmony, all common in many Norrland dialects. Nasal consonants have been lost before a following plosive, with subsequent vowel nasalization. Like many other Norrland dialects, it has also innovated an extended use of the definite form and a preproprial article before proper names.

The Nederkalix dialect is most closely related to other traditional dialects in Norrbotten, especially the neighboring Överkalix dialect in the north. The three parishes constituted one single Kalix parish until the mid 17th century, when Överkalix parish split from Nederkalix, and the two dialects diverged. The Nederkalix and Överkalix dialects are however often considered to be mutually unintelligible.

The oldest preserved manuscripts in the Kalix dialect is an 1879 description of the area, a text which is used as a standard of genuinity. The Kalix dialect was first described by a thesis work by Hulda Rutberg, starting the year 1908 and presented at Uppsala University in 1924. The book contains many words and an extensive description of phonology and grammar. The language is also covered in later documentation, and by many recordings from the 1960s. The work of communities such as Föreningen Kalix Bygdemål, founded 1992, has kept collecting words and expressions to an extensive word lexicon, and is still active today.

The Kalix dialect has, according to Rutberg, 18 vowel monophthongs, 10 vowel diphthongs, and 29 consonants.

Three grammatical genders exist:

Basically, words that in their definite form end with an "n" are masculine, an "e" is neuter, and all vowel except "e" are feminine.