The Lomstjønna Nature Reserve (Norwegian: Lomstjønna naturreservat) is located on Harøya island in the municipality of Ålesund in Møre og Romsdal county, Norway.

Lomstjønna),[4] located in a hilly and nutrient-poor bog landscape that is flat and uniform.

Several bird species that prefer coastal heaths nest here: the greylag goose, European golden plover, sandpipers, and gulls.

There are also some ducks and some special species such as the red-necked phalarope and Lapland longspur.

The reserve is one of six natural areas that were included in the Harøya Wetlands System Ramsar site, which was established in 1996.