The Lakes Plain languages are a family of Papuan languages, spoken in the Lakes Plain of Indonesian New Guinea. They are notable for being heavily tonal and for their lack of nasal consonants.

The Lakes Plain languages were tentatively grouped by Stephen Wurm with the Tor languages in his Trans–New Guinea proposal. Clouse (1997) rejected this connection to the Tor languages and grouped them with the Geelvink Bay languages. Malcolm Ross classifies the languages as an independent family, a position confirmed by Timothy Usher.

Because of the apparent phonological similarities and sharing of stable basic words such as ‘louse’, William A. Foley speculates the potential likelihood of a distant relationship shared between the Skou and Lakes Plain families, but no formal proposals linking the two families have been made due to insufficient evidence. Additionally according to Foley, based on some lexical and phonological similarities, the Keuw language (currently unclassified) may also possibly share a deep relationship with the Lakes Plain languages.

Like the East Cenderawasih Bay, Trans-New Guinea, and South Bougainville language families, Lakes Plain languages have ergative case marking systems. In contrast, most languages of northern Papua New Guinea have accusative case marking systems.

Clouse (1997, p. 155) internally classifies the Lakes Plain family as:

Clouse concludes that the East Geelvink Bay languages are the most closely related to the Lakes Plain languages, forming a wider Geelvink Bay phylum with it.

The Lakes Plain languages as classified by Usher are as follows:

Not included in the above classification, Kaiy, Kwerisa, Doutai and Waritai are presumably also Central Lakes Plain; the same for Obokuitai and Biritai. Clouse had placed them closest to Papasena and to Eritai, respectively, and they might form dialect clusters with those languages.