Paleo-Laplandic is a hypothetical group of extinct but related languages spoken in Sápmi (northern Scandinavia). The speakers of Paleo-Laplandic languages switched to Sámi languages, and the languages became extinct around 500 CE. A considerable amount of words in Sámi languages originate from Paleo-Laplandic;^[1] more than 1,000 loanwords from Paleo-Laplandic likely exist. Many toponyms in Sápmi originate from Paleo-Laplandic. Because Sámi language etymologies for reindeers have preserved a large number of words from Paleo-Laplandic, this suggests that Paleo-Laplandic groups influenced Sámi culture.^[2]

Due to irregular correspondences in Sámi loanwords from Paleo-Laplandic, it can be theorized that the words were borrowed from distinct but related languages that were characterized in the west by an s-type sibilant, while in the east it was an š-type sibilant.

Many words relating to the environment or reindeer such as ája ("spring") are likely loanwords from Paleo-Laplandic into Sámi.^[3][4] The substrate words have no apparent parallels to any known language. Linguist Jurij Kuzmenko [de] compared them with the Pre-Germanic substrate words but found no similarities aside from a distinction between central and peripheral accentuation.^[5]

A large amount of Sami root words that start with the Č or K sounds tend to be from Paleo-Laplandic. Paleo-Laplandic like Sami had many different words for describing different types of Animals, Weather, and Geographical features they often encountered.^[6]

The time from 1 AD to 700 AD was a time of massive change in Sapmi, as Sami people migrated north from Southern Finland and Karelia to northern Fennoscandia. During this process the Paleo-Laplandic language was supplanted by Proto-Sami, though it is unclear if Paleo-Laplandic had any contact with Old Norse.^[6]

• Pre-Finno-Ugric substrate